Mastocitoma cutâneo canino após mastocitose acidental induzida por opioide: Relato de caso / Canine cutaneous mastocytoma after accidental opioid-induced mastocytosis: Case report

A aproximação entre petse tutores está cada vez mais presente na rotina atual das residências familiares. Essa aproximação aumenta a observação de quaisquer alterações físicas ou comportamentais dos animais levando-o a buscar um médico veterinário quando necessário. O papel do clínico, oncologista e do patologista veterinário vem a ser de extrema importância para detecção das neoplasias em suas fases iniciais. A utilização dos meios de diagnósticos complementares para os casos de neoplasias é de fundamental importância para ter ciência do prognóstico do animal e de qual tratamento será o melhor tratamento para os casos abordados. O mastocitoma é a neoplasia cutânea mais frequente do cão, é uma neoplasia maligna e sua etiologia é pouco compreendida. Independente do sexo, atingem machos e fêmeas, porém se apresentam de forma mais agressiva em machos. O diagnóstico, geralmente é estabelecido por meio de exames complementares, associados aos sinaisclínicos, devendo sempre prezar pelo diagnóstico precoce para que haja maior êxito no tratamento.O exame citológico para o diagnóstico de mastocitoma é um dos métodos mais eficientes e de baixo custo, sendo complementado pelo exame histopatológico para agraduação de malignidade e estadiamento da doença. Preconiza-se a associação da cirurgia com o tratamento quimioterápico com terapia antiblástica e eletroquimioterapia para um melhor prognóstico. O objetivo deste trabalho foi relatar um caso de mastocitoma cutâneo após um erro primário de manejo clinico, em um canino, macho, nove anos, da raça American Pitbull Terrier, trazendo sua complexidade e bases dos meios de diagnóstico(AU)

The approximation between pets and tutors is increasingly present in the current routine of family homes. This approach increases the observation of physical or behavioral changes in animals, leading them to seek a veterinarian when necessary. The role of the clinician, oncologist and veterinary pathologist is extremely important for the detection of neoplasms in their early stages. The use of complementary diagnostic means for cases of neoplasms is of fundamental importance to be aware of the animal's prognosis and which treatment will be the best treatment for the cases examined. Mastocytoma is the most frequent skin neoplasm in dogs, it is a malignant neoplasm and its etiology is poorly understood. Regardless of gender, they affect males and females, but are more aggressive in males. The diagnosis is usually established through complementary exams, associated with clinical signs. Cytological examination for the diagnosis of mast cell tumor is an inexpensive method and one of the most efficient methods, being complemented by histopathological examination for its evolution of malignancy and disease staging, recommended the association of surgery with chemotherapy treatment with antiblastic therapy and electrochemotherapy for better prognoses. The aim of this study was to report a case of cutaneous mastocytoma after a primary error in clinical management, in a canine, male, nine years old, of the American Pitbull Terrier breed, bringing its complexity and bases of the means of diagnosis(AU)

Carcinoma de células escamosas em gato - tratamento com quimioterapia metronômica / Squamous cell carcinoma in a cat - treatment with metronomic chemotherapy

Background: Squamous cell carcinoma (SCC) is a malignant neoplasm associated with prolonged exposure to ultraviolet light and lack of skin pigment in white-coated animals. The disease diagnosis is based on the animal's history, clinical signs and histopathology of the samples collected. The therapeutic alternatives are diverse. Among them, one of the most used is the metronomic chemotherapy which is based on the use of cytostatics drugs, applied in low and frequent doses for a longer period of time. One of the mechanisms of action of this type of therapy is the decrease in angiogenesis. Non-steroidal anti-inflammatory drugs (NSAIDs) are simultaneously used to maximize the angiogenic effect. The objective of this study is to report the results of a treatment accomplised with metronomic chemotherapy (cyclophosphamide with meloxicam) in a domestic feline which presented a squamous cell tumor. Case: A 7-year-old female cat, mixed breed, not neutered, weighing 3.5 kg, was assisted at the Veterinary Specialties Teaching Clinic (CEEV) of the Technical University of Machala (UTMACH), presenting bilateral ulcerative lesion in the nasal plane for 5 months. Chronic exposure to sunlight is referred to in the patient's anamnesis. Aspiration cytology performed in the patient revealed an inflammatory process with a predominance of neutrophils and macrophages, and showed absence of neoplastic cells. A treatment based on antibiotics and corticosteroids was adopted. As there were no favorable results, an excisional biopsy procedure was chosen to collect the affected tissues. The result of the histopathological analysis was a level 2 squamous cell carcinoma (SCC). The initial treatment consisted of surgical removal of the tumor and later the use of metronomic chemotherapy based on Cyclophosphamide, Meloxicam, DHA (docosahexaenoic acid) and Sucralfate for 5 months was adopted. At the beginning of the second phase of treatment, the patient developed a macula that progressively diminished. Currently, the patient does not have any recurrence of the diagnosed neoplasm. Discussion: The diagnosis of squamous cell carcinoma was based on clinical and histopathological findings. The macroscopic lesions were crusted ulcers that do not heal in the nasal plane and auricular pavilion, as reported in the literature. SCC is characterized by the infiltration of squamous cells in the dermal layer of the skin, forming epithelial islands with keratin pearls. The histopathological findings of this case present the same characteristics. The climatic conditions of Ecuador, high temperatures with greater incidence of sunlight, hypopigmented areas of the animal's body and chronic exposure to solar radiation are risk factors present in this case that foster the development of this malignant neoplasm. There are multiple treatments to be introduced in this sort of pathology. In this case, surgical removal of the tumor was adopted, followed by metronomic chemotherapy based on cyclophosphamide at 10 mg/m2 and meloxicam at a 0.05 mg/kg per day for a period of time of five months, obtaining favorable results and absence of recurrence. Despite metronomic chemotherapy being easy to administer, with fewer side effects, which includes a better acceptance of care takers who are reluctant to administer conventional chemotherapy, further studies are still necessary in what concerns certain variables such as age, carcinoma level, appropriate dosages and drugs according to each neoplasm.

Cutaneous anaplastic large T-cell lymphoma in a cat: case report / Linfoma cutâneo anaplásico de grandes células T em um gato: relato de caso

Lymphoma is the most common lymphoproliferative disorder in cats. However, cutaneous lymphomas are uncommon in this species and can be classified as epitheliotropic or non-epitheliotropic. Epitheliotropic lymphomas are typically of T-cells and have tropism for epidermis and/or adnexal epithelium. Non-epitheliotropic lymphomas can be of either T-cell or B-cell and involve predominantly the dermis. The present study describes a case of multifocal cutaneous anaplastic large T-cell lymphoma. The skin nodules were multiple and variable in size, alopecic and erythematous in appearance and randomly distributed. Immunohistochemistry revealed positivity for the CD3 antigen, consistent with T-lymphocytes. This neoplasm should be remembered whenever multiple cutaneous nodules are observed in cats.

Linfoma é o distúrbio linfoproliferativo mais comumente observado em gatos. Contudo, linfomas cutâneos são incomuns nessa espécie e podem ser classificados como epiteliotrópico ou não epiteliotrópico. Linfomas epiteliotrópicos são tipicamente originários de células T e têm tropismo pela epiderme e/ou pelo epitélio anexial. Linfomas não epiteliotrópicos podem ser originários de células T ou B e envolvem predominantemente a derme. No presente trabalho, descreve-se um caso de linfoma cutâneo multifocal anaplásico de grandes células T em um gato. Os nódulos cutâneos eram múltiplos, de dimensões variáveis, alopécicos, eritematosos e aleatoriamente distribuídos. A imuno-histoquímica revelou positividade para CD3, sendo consistente com origem em linfócitos T. Essa neoplasia deve ser lembrada sempre que forem observados nódulos cutâneos múltiplos em gatos.

Cutaneous epitheliotropic lymphoma in a Lhasa Apso

Background: Lymphoma neoplasms originate from the lymphocytes. Anatomically, these tumors can be classified into multicentric, digestive, mediastinal, and cutaneous forms. The etiology of cutaneous lymphoma remains unclear; however, it has been associated with chronic skin inflammation. The definitive diagnosis is based on histological analysis and immunohistochemistry, although fine-needle aspiration cytology has shown good results. The aim of this paper is to describe the clinicopathological aspects of a case of cutaneous epitheliotropic T cell lymphoma, classified as mycosis fungoides, in a Lhasa Apso dog. Case: A 8-year-old bitch Lhasa Apso with multiple non-pruritic skin nodules and history of 10-day evolution was referred to the Veterinary Hospital of the Centro Universitário do Espírito Santo (UNESC), Colatina, ES, Brazil. The nodules were erythematous, exophytic, firm, circumscribed, and measured 0.2-4 cm in diameter in locations throughout the animal's body. An incisional biopsy was performed with an 8-mm punch and sent for histopathological examination. An infiltrative, poorly demarcated, non-encapsulated, densely cellular neoplasm, which was replacing the dermal collagen and displacing the adnexa, was observed in the dermis. The tumor was composed of a population of round cells, with generally distinct cell borders and a small-to-moderate amount of eosinophilic cytoplasm. The nuclei were irregularly rounded and occasionally edentulous, with vesicular chromatin, a visible nucleus, and 11 mitotic figures in an area of 2.37 mm2 . The immunohistochemical test, which was positive for the CD3 marker, confirmed the diagnosis of T cell lymphoma. On an ultrasound to identify metastasis, the liver showed heterogeneous parenchyma, heterogeneous expansive formation, areas of cavitary appearance, and cytology compatible with lymphoma. Antineoplastic chemotherapy was administered using the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone). However, the animal died after 45 days. Discussion: A diagnosis of the mycosis fungoides type of cutaneous epitheliotropic T cell lymphoma was established based on clinical, laboratory, anatomopathological, and immunohistochemical findings. Pruritus is a common clinical condition in animals with mycosis fungoides, particularly in those with the erythrodermic form of the disease. Epitheliotropic lymphomas have no sexual or racial predilections and usually affect dogs over 9 years of age. The Cocker Spaniel, English Bulldog, Boxer, Golden Retriever, Scottish Terrier, Briard, English Springer Spaniel, Beagle, German Shepherd, and English Cocker Spaniel breeds are frequently affected by these lymphomas. These neoplasms can have a primary skin origin, or they can be secondary and associated with lymphoma found elsewhere in the body. Chemotherapy is the treatment of choice, especially in cases with multifocal distribution. Protocol preference varies with disease stage, patient clinical and laboratory conditions, and the degree of toxicity. Commonly used chemotherapy regimens include L-CHOP (vincristine, cyclophosphamide, doxorubicin, L-asparaginase, and prednisolone), CHOP, COP (cyclophosphamide, vincristine, and prednisone), LAP (lomustine, L-asparaginase, and prednisolone), LOPP (lomustine, vincristine, procarbazine, prednisolone), chlorambucil, and prednisolone. The prognosis of canine epitheliotropic cutaneous lymphoma is unfavorable, with a survival time ranging from a few months to 2 years. The animal in this study survived for 105 days. In addition, epitheliotropic cutaneous T cell lymphoma is aggressive, which may result in a shorter survival time in animals affected by this type of tumor.

Pilomatricoma benigno em cão da raça Shih-Tzu / Benign pilomatricoma in a Shih-Tzu dog

Background: Pilomatricomas are neoplasms of hair follicles, located in the hair bulb, and the incidence is uncommon in the clinical-surgical clinical routine of dogs and cats. It commonly affects adult animals, with no predisposition to sex or race, and is mainly located in the neck, back, and tail region. The diagnosis is made by histopathological examination, where cells are observed in which their nucleus does not stain with hematoxylin and eosin - empty nucleus. The present work aimed to report a case of benign pilomatricoma since it is a rare condition in dogs and cats and, consequently, there is little information in the literature. Case: A 6-year-old male Shih-Tzu dog, not submitted to surgical contraception, weighing 6.9 kg, was treated at the Veterinary School Hospital (HVE) of the North Parana State University (UENP), Bandeirantes, PR, Brazil, with a history of nodules in the tail region, lasting 6 months. On physical examination, no changes were identified in the patient's physiological parameters. However, the presence of neoformations in the distal and medial region of the tail, similar to a nail, adherent, non-ulcerated and non-alopecic, and absence of pruritus or self-mutilation were identified. Vaccination and deworming were updated. Hematological examination, serum biochemicals (urea, creatinine, alanine aminotransferase, alkaline phosphatase, and albumin), and abdominal ultrasound showed no changes. According to the clinical and laboratory signs, it was decided to perform an excisional biopsy, using a caudectomy, for subsequent histopathological examination. The specimens were fixed in 10% formaldehyde and sent for histopathological examination. Histological examination was compatible with benign pilomatricoma. Postoperatively, cephalexin, dipyrone, tramadol hydrochloride, and meloxicam were prescribed, surgical wound cleaning, and the use of an Elizabethan collar until the suture was removed. After 10 days of the surgical procedure, the patient was asked to remove the sutures, and no changes were identified regarding the physiological parameters and blood count. Discussion: Pilomatricomas are commonly benign neoplasms arising from the germ cells of the follicular matrix. They present dermal or subdermal forms, with several cystic structures which are surrounded by keratinocytes, similar to the matrix cells of an anagen hair follicle, more keratinized and firmer areas, corroborating the results of the present report. In the ultrasound examination, the presence of intra-abdominal metastases was not identified, which is consistent with the literature, since in this type of neoplasm it is not common to identify foci of intra-abdominal and thoracic metastases. In the present report, immunohistochemistry was not used, even though it is used to differentiate follicular neoplasms from pilomatricomas. However, histopathological examination is considered the best method for the definitive diagnosis of pilomatricomas in dogs. It was concluded that the surgical treatment through excisional biopsy, with safety margins of 2 cm, was effective as a therapeutic method in the case of benign pilomatricoma, and the definitive diagnosis must be made through histopathological examination.

Cutaneous myxoma in broiler chicken detected during slaughtering

Background: A cutaneous or superficial myxoma is a benign neoplasm of dermal or subcutaneous fibroblast origin. Although rare, it has been previously described in several species, including poultry. It presents as a single node or soft mass with a gelatinous cut surface. Histopathological analysis is essential for diagnosis and to differentiate it from other mesenchymal neoplasms and inflammatory or degenerative processes. Microscopically, it consists of dermal or subcutaneous lobules of plump, stellate, or spindle-shaped, bland-looking cells embedded in a basophilic myxoid matrix. This report describes the pathological findings in a rare case of cutaneous myxoma in a 42-day-old broiler flock. Cases: During ante mortem inspection of a 42-day-old broiler flock at a slaughterhouse under the authority of the Federal Inspection Service (southern Brazil), nodular lesions or encrusted areas with yellow and black areas were observed in the head skin of less than 1% of animals. These lesions, approximately 0.5 cm in diameter, were observed on the comb, in the periocular skin region, and close to the animals' nostrils. During the breeding period, no health or epidemiological events were observed. Fragments of the lesions in the comb and periocular skin were collected and fixed in buffered 10% formalin. The samples were sent to the laboratory, routinely processed, and stained with hematoxylin and eosin and Alcian blue. Microscopically, the lesions consisted of irregular multifocal proliferation of connective tissue showing spindle cells with poorly demarcated borders and scarce cytoplasm in a slightly basophilic myxoid aspect matrix. The adjacent epidermis is compressed due to neoplastic proliferation. No areas of epithelial hyperplasia or inclusion bodies were observed. According to the pathologic description and considering its descriptive epidemiology, our main clinical suspicion was cutaneous fowl pox, a pathology characterized by the appearance of nodules in regions devoid of feathers. However, the microscopic changes observed were compatible with those described for cutaneous myxomas. In addition, the extracellular matrix was positive for Alcian Blue staining, which is an indicator of myxoma. In the present case, the SIF did not report the same macroscopic lesions in other flocks of the same origin. Discussion: Connective tissue tumors, including myxomas, occur considerably less frequently under field conditions. In addition, these neoplasms are more frequent in mature birds and are not usually described in broilers, as observed in this report. The cutaneous myxoma described in broilers is usually a sporadic neoplasm that does not cause zootechnical losses, as observed in the case report. Its etiology is unknown and has been associated with various factors, such as local trauma and foreign bodies. Some fragments of plant material from the breeding environment were microscopically detected in the encrusted areas, which may indicate previous trauma or a foreign body. Myxoma has been associated with avian leukosis virus (ALV) subgroup A, but SIF did not report the same macroscopic lesions in other flocks of the same breeder hen's origin in the present case. Furthermore, sporadic connective tissue tumors associated with the virus occur in mature chickens but not in broilers. Myxoma lesions should be considered in the differential diagnosis of other connective tissue tumors and infectious agents that cause lesions in the skin and subcutaneous tissue.

Carcinoma de células escamosas (cce) em cão na região prepucial: relato de caso / Squamous cell carcinoma (scc) in dog in the preputial region: case report / Carcinoma de células escamosas (cce) en perro de la región prepucial: reporte de un caso

A expectativa de vida dos animais de companhia vem aumentando devido as mudanças comportamentais e de cuidados dos tutores. Em analogia, com as idades cada vez mais avançadas, é comum o desenvolvimento de doenças associadas, sendo o tumor o mais comum entre elas. Todavia, as neoplasias mais comuns na clínica de pequenos animais estão associadas ao sistema tegumentar. O carcinoma de células escamosas (CCE), ou carcinoma espinocelular, é uma neoplasia de epitélio, maligno, de crescimento lento e de baixo potencial metastático. Sua etiologia ainda não é precisamente conhecida e a causa exógena mais comum e descrita pela literatura é a exposição à luz ultravioleta, gerando consequentes lesões nas estruturas genéticas e imunogênicas na pele. Além disso, essas lesões apresentam-se de forma mais comum em animais de pelagem clara, com grande exposição solar e em área anatômicas hipopigmentadas. O prognóstico varia de acordo com a localização e o estágio clínico, sendo favorável o diagnóstico realizado precocemente, e o tratamento consiste na avaliação clínica seguida do protocolo adequado O presente relato de caso tem como objetivo principal reunir e discutir informações associadas sobre o carcinoma de células escamosas em caninos e felinos, abordando aspectos clínicos e patológicos, a fim de facilitar o raciocínio sobre o CCE, desde sua abordagem inicial, até seu diagnóstico final e estadiamento.(AU)

The life expectancy of companion animals has been increasing due to behavioral and care changes of the guardians. In analogy, with the increasingly advanced ages, the development of associated diseases is common, the tumor being the most common among them. However, the most common neoplasms in the small animal clinic are associated with the integumentary system. Squamous cell carcinoma (SCC), or squamous cell carcinoma, is a malignant, slow-growing, low-potential metastatic epithelial neoplasm. Its etiology is not yet precisely known and the most common exogenous cause described by the literature is exposure to ultraviolet light, generating consequent lesions on the genetic and immunogenic structures in the skin. In addition, these lesions are more common in light-haired animals, with high exposure to the sun, and in hypopigmented anatomical areas. The prognosis varies according to the location and clinical stage, being favorable to the early diagnosis, and the treatment consists in the clinical evaluation followed by the appropriate protocol. The present case report has as its main objective to gather and discuss associated information about squamous cell carcinoma in canines and cats, addressing clinical and pathological aspects, in order to facilitate the reasoning about the CCE, from its initial approach, to its final diagnosis and staging.(AU)

La esperanza de vida de los animales de compañía ha ido en aumento debido a los cambios de comportamiento y cuidado de los guardianes. Por analogía, con las edades cada vez más avanzadas, el desarrollo de enfermedades asociadas es común, siendo el tumor el más común entre ellos. Sin embargo, las neoplasias más comunes en la clínica de animales pequeños se asocian con el sistema tegumentario. El carcinoma epidermoide (CCE), o carcinoma epidermoide, es una neoplasia epitelial metastásica maligna de crecimiento lento y bajo potencial. Su etiología aún no se conoce con precisión y la causa exógena más común descrita por la literatura es la exposición a la luz ultravioleta, generando lesiones consecuentes en las estructuras genéticas e inmunogénicas de la piel. Además, estas lesiones son más comunes en animales de pelo claro, con alta exposición al sol, y en áreas anatómicas hipopigmentadas. El pronóstico varía según la localización y el estadio clínico, siendo favorable al diagnóstico precoz, y el tratamiento consiste en la evaluación clínica seguida del protocolo adecuado. El presente reporte de caso tiene como objetivo principal reunir y discutir información asociada sobre el carcinoma epidermoide en caninos y gatos, abordando aspectos clínicos y patológicos, con el fin de facilitar el razonamiento sobre el CCE, desde su abordaje inicial, hasta su diagnóstico final y estadificación.(AU)

Epididymal primary mast cell tumor in a dog

Background: In the literature, there are a few descriptions of epididymis neoplasia in domestic animals, especially considering primary tumors. In the few reports found in literature, the lesions were a consequence of the invasion of testicular or paratesticular neoplasia, as a papillar carcinoma in a dog's and a bull's epididymis, and mesenchymal tumors - fibrome/ fibrosarcoma, leiomyoma/leiosarcome. On the other hand, mast cell tumors are the second most prevalent neoplasia in dogs in Brazil, affecting especially the skin. The aim of this report is to describe for the first time a low malignancy mast cell tumor in a mixed-breed dog's epididymis, without metastasis or recurrence in a 2-year follow-up period. Case: A 10-year-old male mixed-breed dog was presented for pre-surgical evaluation for elective orchiectomy. In the physical examination, an increase in the volume of approximately 2 cm with an irregular appearance was identified on palpation in the cranial pole of the left testis. In the trans surgical period, an increase in testicular volume (4 cm long x 2 cm wide) was observed, with a firm consistency in the region of the vas deferens with macroscopic changes in the region. The testis was sectioned, and the fragments were sent for histopathological evaluation in 10% buffered formaldehyde. There was a fairly cellular circumscribed neoplastic infiltrate, distributed in a sheet and separated by fibrovascular stroma, and rounded neoplastic cells with a moderate amount of basophilic cytoplasmic granulation, and discrete anisocytosis and anisokaryosis. The nuclei were rounded with vesicular chromatin with 1 or 2 distinct nucleoli. No mitosis figures were observed in 10 high power fields (400x). Few eosinophils were distributed throughout the neoplastic cell population. Immunohistochemistry demonstrated immunostaining for KIT protein with perimembranous staining in 95% of neoplastic mast cells, giving a KIT 1 pattern. There was no positive nuclear staining for Ki67 in any cell of the histological sections examined. A grade II mast cell tumor (low grade of malignancy) was diagnosed. After diagnosis, the animal underwent radiographic evaluation of the chest and abdominal ultrasound, and a new physical inspection in search of nodules, plaques, skin lesions, or subcutaneous masses. There were no metastases in the thorax and abdominal cavity, nor physical alterations, and it can be inferred that the epididymis was the primary site of the mast cell tumor. After 2 years of orchiectomy, there were no recurrences, and no chemotherapy treatment was performed. Discussion: Extracutaneous mast cell tumors are uncommon in animals, but have been reported in oral and nasal mucosa, nasopharynx, larynx, trachea, intestine, visceral lymph nodes, spleen, liver, spinal cord, intestine, ureter, conjunctiva, lung and more recently in tear gland of the third eyelid. However, in the authors' assessment, this is the first description of mast cell tumor in the epididymis in dogs. The diagnosis was established by histopathological examination, which revealed a grade II epididymal mast cell tumor and immunohistochemical evaluation (KIT and Ki-67) as being of low aggressiveness. The diagnosis of a primary tumor was confirmed since the staging was established after the histopathological diagnosis, involving chest radiography, abdominal ultrasound, cutaneous evaluation in search of nodules, plaques, cutaneous and subcutaneous lesions, and did not reveal other abnormalities or metastases not identified in the preoperative evaluation. In addition, immunostaining with KIT and Ki-67 reaffirmed the low degree of malignancy and the potential for metastases, which can be observed by the asymptomatic follow-up of the patient 2 years after the surgical excision.

Multilobular tumor of bone in bitches: clinical, histopathological, immunohistochemical and overall survival aspects

Background: Multilobular tumor of bone (MTB) is an unusual neoplasm with variable biologic behavior which originates primarily in bone tissues. Radiographs computed tomography (CT), and magnetic resonance imaging (MRI) are useful in diagnoses and surgical planning. Tumor removal with wide surgical margins is the treatment of choice. Immunohistochemistry has been shown as an important tool in veterinary oncology to define therapeutic and prognostic decisions. The goal of this study was to report 2 distinct cases of multilobular tumor of bone, their Cox-2 and Mib-1 immunohistochemical profile and its impact on overall survival. Case: Two bitches were presented at the Oncology Department of the Veterinary Hospital in the Veterinary School of Universidade Federal de Minas Gerais (UFMG). Both had a history of a progressive, painless, circumscribed, and firm facial mass. The 1st patient was a 8-year-old intact bitch mixed breed, weighing 50 kg, that presented a fast growing right infraorbital 3-cm mass, causing eye displacement. The 2nd patient was a 7-year-old spayed bitch Labrador retriever, weighing 28 kg, that presented a left temporal 8-cm mass. Neurologic examination of both bitches was normal. Skin over the nodules was strained, but with no ulceration. Radiographic exams of the head revealed lytic and proliferative bone reaction, with loss of cortical definition in both cases. These alterations were seen on the left zygomatic arch of the retrobulbar region, involving part of the mandible and of the nasal sinus lateral frontal bone in 1st patient, and on the right temporal process of the zygomatic bone in 2nd patient. The last one, also showed a granular solid mass with little contact with skull bones. Complete blood count, biochemistry profile, electrocardiogram, and 3-view thoracic radiographs were performed. Results were within normal ranges for the species and no signs of metastasis was seen on the radiographs. Location, size, and density of the mass, adjacent tissue compression, absence of cranial invasion, and lymph node size were rigorously evaluated with CT, allowing an individualized surgical planning to achieve complete mass removal and maintenance of the function of adjacent structures. Both animals were submitted to surgery. Both tumors were fixed on 10% neutral buffered formalin and sent to the Animal Pathology Department of UFMG for histopathological examination and margin assessment. Both tumors were diagnosed as grade I MTB. Tumor immunohistochemistry was performed to identify prognostic factors that could be used to better define therapeutic treatments and to try to clarify the discrepancy in disease progression between both tumors. The 1st patient expressed 20% of Mib-1 and was considered score 2 of Cox-2. The 2nd one expressed 5% of Mib-1 and was considered score 1 of Cox-2. Considering the diagnoses and histological characteristics of the tumors, it was decided for clinical follow-up of patients without additional therapeutic complementation. Even considering incomplete surgical margins in 2nd patient, adjuvant chemotherapy was not performed, due to low mitotic index and low histological grade. The 1st patient had an overall survival of 240 days, and death was due to recurrence and disease progression; and the 2nd did not show recurrence nor metastasis after 1200 days. Discussion: Proper and individualized surgical planning and histopathological evaluation are extremely important to guide treatment decisions. However, immunohistochemistry can be important in MTB cases, to help define which patients should be submitted to surgery alone and which patients could be benefited from adjuvant chemotherapy.

Malignant tumor of peripheral nerve sheath in the thoracolumbar region in a cat

Background: In veterinary medicine, peripheral nerve tumors (PNST) are classified from the cellular pattern and as benign and malignant (MPNST). The majorities of cases are benign and usually involve the skin and subcutaneous tissue of the head, neck, and limbs. Animals with MPTNS usually have spinal cord and spinal canal involvement and are also described in the small and large intestine, oral cavity, perirenal region, and urinary bladder. Treatment is performed according to the location of the neoplasm and metastasis is rarely described. The present article aims to report a case of a malignant tumor in the peripheral nerve sheath of a cat. Case: A 8-year-old domestic cat was presented with a history of progressive paresis in the pelvic limbs. On neurological evaluation, proprioceptive ataxia and proprioception deficit in the pelvic limbs were observed, suggestive of thoracolumbar injury. Blood work and serum biochemistry showed results within the reference for the species and the bi-directional immunochromatography test for FIV and FeLV were negative. The radiographs of the thoracolumbar segment did not show significant changes. Myelography with iodinated contrast and collection of cerebrospinal fluid (CSF) were performed. On myelography examination, iodinated contrast loss was found between the 6th and 7th thoracic vertebrae, while the CSF analysis was normal. The patient underwent laminectomy and durotomy for excision of a mass found dorsally to the spinal cord, with intradural location. The tumor was sent for histopathological examination. Microscopic analysis showed neoplastic proliferation of spindle-shaped cells with predominance of the Antoni A pattern. Immunohistochemical analysis demonstrated intense cytoplasmic staining of the neoplastic cells for vimentin and S100 protein. Based on these findings, the diagnosis of malignant peripheral nerve sheath tumor was made. Radiotherapy was suggested as adjuvant treatment after surgical procedure. However, the owner refuse to follow this recommendation due to cost restriction. The patient had a satisfactory clinical recovery, he has no longer presented proprioceptive ataxia or proprioception deficits in three months after the surgical procedure. Discussion: In the case described, the feline patient presented a history, clinical signs, and findings in the myelography exam related to MPNST in the region of the vertebral canal. This neoplasm usually involves the spinal canal or spinal cord, but has been described in other locations, such in the small and large intestine, oral cavity, perirenal region, and urinary bladder. Based on the findings of the physical examination and complementary exams, a surgical procedure was recommended. Then, laminectomy and dutoromy were performed to remove the mass. The treatment described in the literature in cases of MPTNS is surgery, which can be curative, but in some cases, the use of radiotherapy may be necessary. The histological patterns observed in this neoplasm are the Antoni A and B, in the case described the Antoni A pattern was observed. The definitive diagnosis was made by immunohistochemistry with vimentin and S100 protein. MPNST are few described in the thoracolumbar region in cats. The surgical treatment was curative, where improvement of the clinical signs could be observed three months after surgery. In addition, monitoring of patients is recommended to ascertain relapses and metastases.

Concomitant occurrence of multicentric hemangiosarcoma and histiocytic sarcoma in a dog

Histiocytic sarcoma (HS) is uncommon malignant neoplasia of round cells with marked predilection in Rottweiler and Bernese Mountain. The disseminated form, which mainly affects the spleen, lungs, lymph nodes, bone marrow, skin, and subcutis, presents a quick and aggressive clinical behavior. Hemangiosarcoma (HAS) is a malignant neoplasm of endothelial vessel cells commonly reported to affect the right atrium of dogs' hearts. A male Rottweiler, five years old, presented flaccid paraplegia and progressive muscular atrophy in the temporal, masseter, and limbs muscles; Due to the clinical stage of the animal, euthanasia was conducted. During the necroscopic examination, it was noticed that several masses presented different sizes; some were whitish, and others were reddish and spread in multiple organs (lungs, heart, spleen, stomach, kidneys, brain, medulla, skeletal muscle, and pre-scapular lymph node). Microscopically, in some organs such as the stomach, right ventricle, lungs, and medulla, it was noticed a proliferation of myeloid cells, highly cellular, with poor demarcation, no encapsulation, and with the infiltrative growth pattern of cells with high pleomorphism. Numerous tumoral emboli were observed in the spleen, brain, skeletal muscle, and lymph node. These cells were submitted for immunohistochemistry and were positive for CD18 (HS antibody). In the right atrium, liver, and kidney it was observed malignant and infiltrative endothelial proliferation (HSA) and emboli in the medulla. Therefore, we conclude that both neoplasms (HS and HSA) cause the animal's paraplegia due to their embolism and metastasis to the spinal cord and skeletal muscle.(AU)

Tricoblastoma em canino doméstico / Trichoblastoma in a domestic canine

A pele é um órgão complexo constituído por diferentes tipos celulares e possui exposição direta ao meio ambiente, representando uma barreira física do organismo. Devido a tais fatores pode ocorrer o aparecimento de diversos tipos tumorais. Além disso, a pele possui alta capacidade de renovação celular, o que aumenta as chances de mutações em comparação com outros tecidos, o que a torna um lugar favorável para o desenvolvimento de neoplasias. É comum ocorrer nos animais domésticos o desenvolvimento de neoplasias cutâneas, sendo que sua prevalência depende de fatores como genética, idade, raça, relação hormonal, nutrição, entre outros. O tricoblastoma é uma neoplasia benigna cutânea comum em cães e gatos adultos, animais com idade entre seis e nove anos são os mais acometidos, e não existe predisposição em machos e fêmeas. É derivado do folículo piloso primitivo e possui componentes epiteliais e mesenquimais. O tricoblastoma não é considerado agressivo, porém, existem relatos na literatura com características de neoplasia maligna. O tratamento de eleição do tricoblastoma é a exérese cirúrgica total do mesmo, com margens de segurança entre 1 e 2cm. O presente estudo tem como objetivo relatar o caso de um animal atendido no Centro Médico Veterinário do Centro Universitário do Sul de Minas, o qual foi diagnosticado com tricoblastoma.

The skin is a complex organ composed of different cell types and has direct exposure to the environment, representing an organism's physical barrier. Due to such factors, the appearance of several tumor types may occur. In addition, the skin has a high capacity to perform cell renewal, which increases the chances of mutations compared to other tissues, turning it a favorable place for the development of neoplasms. The development of skin neoplasms in domestic animals is a common fact, and their prevalence depends on factors such as genetics, age, race, hormonal relationship, nutrition, among others. Trichoblastoma is a benign cutaneous neoplasm common in adult dogs and cats, animals aged between six and nine years are the most affected, and there is no predisposition in males and females. It is derived from the primitive hair follicle and has epithelial and mesenchymal components. Trichoblastoma is not considered aggressive; however, there are reports in the literature with characteristics of malignant neoplasm. The treatment of choice for trichoblastoma is the total surgical excision, with safety margins between 1 and 2cm. The present study aims to report the case of an animal treated at the Veterinary Medical Center of the University Center of Southern Minas Gerais, which was diagnosed with trichoblastoma.

Cytopathology of cutaneous and subcutaneous neoplasms in feline species: a retrospective study / Citopatologia das neoplasias cutâneas e subcutâneas na espécie felina: estudo retrospectivo

It is estimated that a quarter of all feline neoplasms affect the integumentary system. Cytological examination is of admirable importance for detection of neoplasms in companion animals, being considered a simple and non-invasive method. To date, there are limited information regarding the prevalence of feline skin cancer as well as the use of cytopathology as a diagnostic tool. In this sense, the study aimed to characterize cutaneous and subcutaneous tumors in 192 cats from the archives of a private clinic in São Paulo-SP, Brazil, specialized in the care of felines. Data regarding the animal (breed definition, sex, and age group) and tumor characteristics (biological behavior, cytomorphological category of neoplasm, and cytological suggestion for neoplasm) were obtained in a five-year period. A 95% confidence interval (CI) was estimated to verify the statistical difference between the animal and tumor characteristics. The chi-square test was carried out to verify the association between the tumor biological behavior and animal variables, as well as other tumor characteristics. Most cats were mixed breed and aged 11 to 15 years. Malignant tumors were predominant. A statistical association was observed between cytomorphological category of neoplasm and biological behavior (p<0.001). Mesenchymal (24.5%) and epithelial tumors (25%) presented the highest frequency among those benign and malignant, respectively. The cytological suggestion for neoplasm was also statistically associated with biological behavior (p<0.001). The highest percentage of occurrence of benign and malignant tumors consisted of lipomas (22.9%) and sarcomas (19.3%), respectively.(AU)

Estima-se que um quarto de todas as neoplasias felinas afetam o sistema tegumentar. O exame citológico é impor-tante para detecção de neoplasias em animais de companhia, sendo considerado um método simples e não invasivo. Até o momento, há informações limitadas sobre a prevalência das neoplasias cutâneas felinas, bem como o uso da citopatologia como ferramenta diagnóstica. Nesse sentido, o estudo teve como objetivo caracterizar neoplasias cutâneas e subcutâneas em 192 gatos do arquivo de uma clínica veterinária privada da cidade de São Paulo-SP, Brasil, especializada no atendimento de feli-nos. Dados referentes ao animal (raça, sexo e faixa etária) e características das neoplasias (comportamento biológico, categoria citomorfológica e sugestão citológica) foram obtidos em um período de cinco anos. Foi estimado um intervalo de confiança (IC) de 95% para verificar a diferença estatística entre as características do animal e da neoplasia. O teste do qui-quadrado foi realizado para verificar a associação entre o comportamento biológico da neoplasia e as variáveis dos animais, além de outras características neoplásicas. A maioria dos gatos era sem definição racial e com idade entre 11 e 15 anos. As neoplasias malignas foram predominantes. Foi observada associação estatística entre a categoria citomorfológica e o comportamento biológico da neoplasia (p<0,001). Neoplasias mesenquimais (24,5%) e epiteliais (25%) apresentaram a maior frequência entre os benignos e malignos, respectivamente. A sugestão citológica para neoplasia também foi estatisticamente associada ao comportamento biológico (p<0,001). O maior percentual de ocorrência de tumores benignos e malignos consistiu em lipomas (22,9%) e sar-comas (19,3%), respectivamente.(AU)

A Critical Review of the risk factors associated with Canine Squamous Cell Carcinoma development

Squamous cell carcinoma (SCC) is a common neoplastic skin disease that is highly prevalent in tropical countries. As the skin has a variety of cells, overexposure to environmental factors, such as ultraviolet light, can affect this organ, resulting in malignancies, such as cutaneous SCC, hemangioma, and hemangiosarcoma. SCC arises from keratinocytes in the skin and is locally invasive with low metastatic rates, commonly affecting unpigmented skin in sites with high exposure to sunlight, such as ventral regions. SCC has a variable etiology that is not well understood. Therefore, literature review aimed to critically evaluate the risk factors involved in the SCC development.(AU)

Application of Euphorbia tirucalli sap in sarcoid treatment in horses: case report / Aplicação da seiva de Euphorbia tirucalli no tratamento de sarcoide em equinos: relato de caso

Sarcoid is the most common cutaneous neoplasm in horses, with no established therapy, due to the variable neoplastic manifestation and the oscillating individual response to therapies. The Euphorbia tirucalli plant, known as Aveloz, has terpenes and sterols in its latex with antitumor activity, being widely used in popular medicine. Eight horses were referred to the Veterinary Hospital diagnosed with sarcoid, and they were treated only with an aqueous solution containing Euphorbia tirucalli. The most common location of tumors was base of the ear and pectoral; seven of the eight animals had tumors in more than one region. The intratumoral injection containing the sap of Aveloz was applied until the tumor became turgent, visualizing blackening, dryness, and a detachment of the sarcoid in 24 to 72 hours. The use of Euphorbia tirucalli sap showed 87.5% efficacy in the treatment of sarcoids and adverse effects were observed in the seven animals in which the technique was effective. The treated horses were evaluated for three months to seven years, and none had tumor recurrences. The intralesional application of Euphorbia tirucalli sap has been proved to be effective, safe, and low-cost in the treatment of sarcoid in horses, being a viable alternative for this type of cutaneous neoplasm.

O sarcoide é a neoplasia cutânea mais comum nos equinos, não apresentando uma terapêutica estabelecida, devido à variável manifestação neoplásica e à oscilante resposta individual às terapias. A planta Euphorbia tirucalli, conhecida como Aveloz, possui em sua seiva terpenos e esteróis com atividade antitumoral, sendo amplamente empregada na medicina popular. Foram atendidos, no Hospital Veterinário, oito animais diagnosticados com sarcoide e tratados unicamente com a solução aquosa contendo a seiva de Euphorbia tirucalli. As regiões predominantemente acometidas pelos tumores eram base de orelha e peitoral; sete dos oito animais apresentaram tumores em mais de uma região. A injeção intratumoral contendo Aveloz foi aplicada até a turgência do tumor, visualizando-se, em 24 a 72 horas, o enegrecimento, o ressecamento e o desprendimento do sarcoide. O uso da seiva de Euphorbia tirucalli apresentou 87,5% de eficácia no tratamento de sarcoide, e foram observados efeitos adversos nos sete animais em que a técnica se mostrou eficaz. Os equinos tratados foram acompanhados no intervalo de três mês a sete anos e nenhum apresentou recidivas do tumor. A aplicação intralesional da seiva da Euphorbia tirucalli se apresentou eficaz, segura e de baixo custo no tratamento de sarcoide em equinos, sendo uma alternativa viável para esse tipo de neoplasia cutânea.

Abordagem diagnóstica de mastocitoma cutâneo metastático em canino / Diagnostic approach of metastatic cutaneous mastocytoma in dog

O mastocitoma é uma das neoplasias cutâneas mais comuns que acometem cães. O diagnóstico da doença é baseado em aspectos clínicos e laboratoriais, sendo a citologia e a histopatologia os métodos de eleição. Diante disso, o objetivo deste estudo é relatar a importância da ampla abordagem diagnóstica de mastocitoma cutâneo metastático em uma fêmea canina castrada, atendida no Hospital Veterinário da Universidade Estadual do Ceará, com uma neoformação em membro compatível com mastocitoma. O estadiamento da paciente foi feito através de exames laboratoriais de hemograma completo, e citologia aspirativa de linfonodo regional e medula óssea, que evidenciaram a presença de focos de metástase; bem como do exame de ultrassom abdominal, que evidenciou alterações no parênquima hepático e linfoadenomegalia ilíaco medial direita. Diante das suspeitas, optou-se pela eutanásia da paciente, cujo corpo foi enviado para os exames de necropsia e histopatologia, os quais confirmaram o diagnóstico de mastocitoma cutâneo de alto grau, com metástase em fígado, pulmão, medula e linfonodos. Desta forma pode-se concluir que o mastocitoma cutâneo metastático é uma neoplasia de diagnóstico multifatorial, em que a realização de exames hematológicos associados às análises citológicas, histopatológicas e de imagem são indispensáveis para estabelecer o diagnóstico definitivo para que seja determinada uma melhor conduta terapêutica e prognóstico de pacientes caninos.

Mast cell tumors are one of the most common skin neoplasms that affect dogs. The diagnosis is based on clinical and laboratory aspects, with cytology and histopathology being the preferred methods. Therefore, this study aims to report the importance of the broad diagnostic approach of metastatic cutaneous mastocytoma in a castrated a female dog attended at the Veterinary Hospital of the State University of Ceará, with a neoformation in a member compatible with mast cell tumor. The patient's staging was performed through laboratory tests of complete blood count, aspiration cytology of regional lymph nodes and bone marrow, which showed the presence of focus of metastasis, as well as the abdominal ultrasound examination, which showed changes in the liver parenchymas and right medial iliac lymphadenopathy. Given the suspicions, the patient was euthanized and the body was sent for necropsy and histopathological examination, which confirmed the diagnosis of high-grade cutaneous mast cell tumor, with metastasis in the liver, lung, bone marrow, and lymph nodes. Thus, it can be is concluded that mast cell tumor is a neoplasm of multifactorial diagnosis, where hematological tests associated with cytology, histopathological, and imaging analyses are essential to establish the definitive diagnosis to determine a better therapeutic behavior and prognosis of canine patients.

Congenital cutaneous hemangioma in a newborn lamb

Background: Hemangioma is a benign dermal or subcutaneous endothelial cell tumor composed of vascular spaces of varying sizes filled with erythrocytes and lined with a single layer of uniform endothelial cells. Although the pathogenesis is not well defined, these tumors are considered to result from an imbalance in angiogenesis, leading to uncontrolled proliferation of vascular elements. To the best of our knowledge, there are no reports of congenital cutaneous hemangioma in sheep. This report describes the clinical, laboratory, and pathological findings of a case of congenital hemangioma affecting a newborn lamb. Case: A 5-day-old crossbred (Dorper x Santa Inês) lamb presenting with an ear nodule that expanded in the right ear was necropsied. An expansive subcutaneous nodule was observed macroscopically; it occupied approximately 90% of the right ear and had a crusty, irregular surface. The cut surface had multiple cavitations delimited by firm fibrous tissue and a light yellow-to-translucent content. Microscopically, it showed focally extensive subcutaneous neoplastic proliferation and moderate cellularity; it was formed of vascular beds of varied sizes and supported by moderate fibrocollagenous stroma. Suppurative inflammation was observed in the neoplastic vascular beds with large amounts of free basophilic coccoid bacteria inside macrophages. Immunohistochemistry analysis was performed to confirm the diagnosis. Strong cytoplasmic labeling was observed in neoplastic endothelial cells for CD31 and factor VIII. The Ki67 proliferation marker was positive in approximately 5% of neoplastic cells. The cells did not express smooth muscle actin (1A4) or pan-cytokeratin (AE1AE3). Histological characteristics and immunohistochemistry findings were consistent with those of congenital cutaneous hemangioma, a rare neoplasm in sheep. Discussion: The association of clinical, anatomopathological, and immunohistochemical data enabled the diagnosis of congenital cutaneous hemangioma in the 5-day-old lamb. Reports of vascular tumors in sheep are not frequent in literature and usually involve adult animals with no anatomical site predilection. In sheep, the occurrence of nasotracheal hemangioma in a 2-year-old ewe and gingival hemangioma in a 5-year-old sheep have already been described. A cutaneous extra-neural hemangioblastoma was diagnosed in the ear of a 1-month-old lamb. IHC was also used to confirm the diagnosis of hemangioblastoma. Macroscopically, hemangiomas can present as well-delimited and encapsulated masses that when cut, show a reticulated pattern similar to honeycombs that separate the blood-filled cavities. The present case showed a similar conformation but without enough erythrocytes to result in a bloody appearance. Tumor drainage and the predominance of blood serum in the content possibly made it macroscopically translucent. Microscopically, the hemangioma was classified as cavernous. This morphological variation forms large channels separated by fibrous connective tissue stroma, which may contain inflammatory cells. IHC confirmed the endothelial lining of the cystic cavities and was crucial in excluding differential diagnoses. Thus, factor VIII-related antigen was used as a marker for normal and neoplastic cells, as well as for tumoral and reactive neovascularization, in which neoplastic cells were immuno-expressed for CD31 and Factor VIII. In domestic animals, the association between CD31 and Factor VIII is considered more specific for vascular endothelial cells, differentiating them from cells of lymphatic origin. Congenital cutaneous hemangioma occurs in sheep, and its diagnosis and differentiation can be based on histopathology associated with conventional immunohistochemical panels for vascular neoformation.

Fibroma cutâneo atípico em uma vaca / Atypical cutaneous fibroma in a cow

Background: Cutaneous fibroma is a benign neoplasm affecting the fibroblasts and collagen matrix that develops in the dermis or subcutaneous tissue. This neoplasm is uncommon in cattle, and few reports have described the treatment and resolution of this neoplasm. Despite its benign character, a veterinarian should consider cutaneous fibroma in the differential diagnosis of skin tumors. This report aims to describe a rare case of large fibroma in the scapular region in a cow, with emphasis on the clinical-surgical and anatomopathological aspects of the condition. Case: A 3-year-old Girolando 3/4 cow was attended to at a rural property in Lagamar-MG, Brazil. According to the owner, the animal presented with a small mass in the right scapular region that grew progressively over 1 year and 6 months. Clinical examination revealed an exuberant and painless increase in volume on palpation in the proximal region of the right thoracic limb, which, in its vertical axis, extended from the proximal end of the scapula to near the olecranon tuberosity, and, in its horizontal axis, extended from the 6th intercostal space to the scapulohumeral joint, reaching the dimensions 66 cm and 62 cm, respectively. It presented with multiple nodules that were firm in consistency with extensive areas of ulceration. Neoplasia was suspected, and surgical excision was decided upon. The cow was sedated and restrained in the left lateral decubitus position. Trichotomy and antisepsis of the operative field were performed followed by an infiltrative anesthetic block around the tumor. The tumor was excised maintaining a safety margin of 1 cm. Dermorrhaphy was not possible, and healing by secondary intention was awaited. In the postoperative period, antibiotic therapy with benzathine penicillin, analgesia with meloxicamand dipyrone and daily dressing of the wound were performed. There were no postoperative complications and complete healing occurred approximately 100 days after surgery. One year after the surgical procedure, the owner reported that the cow did not present with recurrence of the neoplasm. The resected tumor weighed 11.2 kg, and, when cut, presented with solid conformation and whitish coloration. Tumor fragments were harvested, fixed in 10% formalin, and sent for histopathological examination, which revealed neoproliferation of remarkable cellular density composed of dense, well vascularized fibrocollagenous connective tissue arranged in multidirectional bundles and undulating pattern. Mild cellular pleomorphism was identified, and no mitosis figures were observed. Alcian blue staining was negative for mucopolysaccharides, differing from Masson's trichrome staining, which widely stained the fibrocollagenous tissue blue. In view of these findings, the diagnosis of cutaneous fibroma was confirmed. Discussion: Cutaneous fibromas are benign neoplasms of fibrous tissue, and they are uncommon in cattle and may be associated with bovine papillomavirus and/or trauma. Although the origin of cutaneous fibroma is not clear, the present report stands out due to the large size of the tumor mass. The complete healing of the surgical wound, the absence of recurrence one year after surgery and the return of the animal to dairy production demonstrate that the surgical treatment was adequate. The macro- and microscopic characteristics of the cutaneous fibroma in this case corroborate with other cases reported in the literature. Large cutaneous fibroma is uncommon in bovines, and may hinder surgical excision and prolong healing time, as well as the complete recovery of the animal. Moreover, the differential diagnosis with other neoplasms of fibroblastic origin is relevant, especially for those with malignant biological behavior, such as fibrosarcoma and myxosarcoma.

Sarcoide em equinos - tratamento com associação de Aciclovir e excisão cirúrgica / Equine sarcoids - treatment with a combination of Acyclovir and surgical excision

Background: Sarcoids are the most frequent skin tumors among horses, causing serious lesions due to their different shapes, sizes, degree of invasiveness and distribution on the body. The pathogenesis of sarcoids is multifactorial, with genetic, viral and environmental involvement, making their treatment complex. The aggressiveness and high rate of recurrence of sarcoids makes it difficult to use an effective treatment, which is why there are several therapeutic routes described in the literature. Aiming to describe and expand sarcoid treatments, this paper reports on the use of acyclovir in the treatment of this type of tumor. Cases: Four horses sent to the Large Animal Veterinary Hospital of the Federal University of Lavras - UFLA were diagnosed and treated for sarcoids. Case 1. Lesions on the right ear, region of the masseter muscle of the right side of the face, neck, vulva and medial aspect of the left pelvic limb. Case 2. Lesion in the left groin region. Case 3. Lesions on the face, masseter muscle region on the left side, mandibular region and right ear pinna. Case 4. Lesion in the lateral region of the left pelvic limb, close to the tarsometatarsal joint. All horses had a diagnosis of sarcoid, which was confirmed by histopathological examination of material collected after surgical excision. Macroscopically, the neoplastic lesions were classified as fibroblastic, verrucous and nodular. The tumors exhibited irregular surfaces, keratinization, and a firm consistency. Their surfaces were alopecic, slightly rough, some of them were ulcerated, and their color ranged from greyish to rosy and reddish. All the tumor masses were surgically excised from the 4 horses, and one sarcoid was treated by thermal cauterization with liquid nitrogen due to the lesion's depth and size. In most cases, the sarcoid removal sites were closed with sutures. Only 2 lesions were not sutured due to the impossibility of bringing the edges of tissue close together, or due to proximity to the tarsometatarsal joint. The surgical wounds were cleaned twice a day with sterile saline solution followed by the topical application of Acyclovir. One of the animals received complementary therapy with Cimetidine. Discussion: The equines recovered completely from their sarcoid treatment, and no recurrences were reported a year later. Thus, the combination of treatments employed for the extirpation of sarcoids proved to have greater chances of success. First, all the tumors were surgically removed with the largest possible margins of safety in order to ensure the elimination of neoplastic cells. In the postoperative period, all the animals received topical treatment of the lesions with acyclovir after surgical resection of the tumors. The drug aided the complete healing of post-surgical wounds, and healing time varied according to the size and depth of the lesion. One tumor was treated with liquid nitrogen after surgical excision of the sarcoid. Another horse was treated with cimetidine over a 3-month period after surgical excision of the neoplasm in order to reduce the sarcoid and prevent its evolution. Surgical excision of the sarcoid associated with topical application of acyclovir ointment showed satisfactory results. Moreover, the combination of surgical excision and administration of liquid nitrogen on the lesion and topical application of acyclovir ointment in the postoperative period also provided good results. Given the complexity of sarcoid treatment and the high recurrence rate of these tumors, the use of combined treatments should be taken into account.

Metastatic vulvar squamous cell carcinoma in a mare

Background: Squamous cell carcinoma (SCC) is a common cutaneous neoplasm in horses, which mainly affects the external genitalia, oral cavity, and periocular region. The development of SCC metastases is rare in these animals, and the most common occurrence is a marked local infiltration. Exposure to ultraviolet rays and skin depigmentation are the main etiological factors of SCC. Definitive diagnosis of the neoplasm is performed through histological examination of lesions. The present report describes the clinical, anatomopathological, and immunohistochemical (IHC) aspects of a case of metastatic SCC, with the vulva as the primary site in a mare. Case: A 17-year-old mare, mixed breed, was referred to the Veterinary Hospital of the Universidade de Passo Fundo (UPF), with history of areas of depigmented skin (pinto coat), and clinical history of anorexia, frequent episodes of colic, and recumbency. During clinical evaluation, heart rate (68 bpm), rectal temperature (38.4ºC), and respiratory rate (48 mpm) were elevated, and the oral mucosa was pale. The mare also had an ulcerated tumor mass involving the vulva, which extended to the inguinal region and involved the mammary gland. A cytological aspirate of the vulvar tumor was performed, in which no neoplastic cells were found. Next, a biopsy of 2 distinct areas of the vulva was performed. The material was sent for anatomopathological examination, which showed markedly pleomorphic malignant squamous cells, with individual keratinization and high mitotic index, organized in trabeculae with rare keratin pearl-like formations. The exam allowed the diagnosis of SCC Grade II. Due to the poor prognosis and high cost of treatment, the owner consented to euthanasia and necropsy examination. During necropsy, the vulvar tumor mass was grayish, firm to hard, infiltrative, and had friable areas. Tumor foci suggestive of metastasis were also observed in inguinal, mesenteric, mediastinal and renal lymph nodes, adrenal glands, lung, pericardium, medullary canal, intercostal muscles, right 15th rib, and tissue surrounding the azygos vein. Samples from all organs were collected for anatomopathological examination. Diagnosis of metastatic vulvar SCC was confirmed through histological and IHC studies, which evaluated the expression of cytokeratins (AE1/ AE3), as well as the proliferative activity of neoplastic cells through the PCNA marker. Discussion: The diagnosis of metastatic SCC was obtained through the observed clinical, necroscopic, histological, and IHC characteristics. This neoplasm usually appears in depigmented regions exposed to ultraviolet light, and older animals are more likely to be affected. The mare in the present case had areas of depigmented skin (pinto coat). The animal was kept in a paddock outdoor and exposed to constant solar radiation. Although rare in horses, manifestation of anorexia, progressive weight loss, and frequent colic episodes and recumbency may be closely related to the multiple sites of metastasis in the present case. The main histological findings of the neoplasm were the dense proliferation of malignant squamous cells with individual keratinization, arranged in a trabecular pattern and with rare formations of keratin pearls, in line with previous studies. During IHC evaluation, the neoplastic cells showed expression of cytokeratins (AE1/AE3), as well as high proliferative activity evidenced by the PCNA marker. Given this background, the present report describes the clinical, anatomopathological, and IHC aspects of a case of metastatic SCC with a primary site in the vulva of a mare.