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.

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.

Cutaneous apocrine adenocarcinoma in a goat

Apocrine neoplasms are rare in goats. This report describes an apocrine adenocarcinoma in a 5-year-old female Boer goat with an ulcerated, exophytic, multilobulated mass on the left dorsolateral cervical area. Histologically, the dermis was effaced and expanded by a poorly demarcated epithelial neoplasm with desmoplasia. Neoplastic cells were arranged in acini with papillary projections into the lumen and had cuboidal or columnar, eosinophilic, occasionally vacuolated cytoplasm. Nuclei were round and had finely stippled chromatin with one nucleolus. Neoplastic cells contained periodic acid-Schiff (PAS)­positive and diastase­resistant, alcian blue­positive cytoplasmic granules. There were 6 mitoses in 2.37 mm2 (equivalent to 10 FN22/40X fields). Histologic and histochemical features in the current case were consistent with a cutaneous apocrine gland adenocarcinoma.(AU)

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)

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.

Metastatic intranasal mastocytoma in a dog

Background: Mast cell tumors (MCTs) are neoplasms originating from mast cells, which can be well or poorly differentiated. They are considered the most commonly diagnosed malignant cutaneous neoplasm in dogs; however, intranasal forms are still little reported. Thus, this study seeks to report a case of unilateral intranasal MCT exhibiting submandibular lymph node metastasis. Case: A 11-year-old-and-4-month-old dog of undefined breed (UB), weighing 41 kg, was referred to the Veterinary Medical Teaching Hospital of the University of Passo Fundo (UPF), in the state of Rio Grande do Sul, Brazil. Presenting a clinical history of bilateral purulent nasal secretion, accompanied by sneezing in the two months prior to admission, in addition to vomiting and diarrhea. Auxiliary tests were requested, including skull X-ray, cytology of the nasal cavity with a swab, and collection of material from the submandibular lymph node directly through cytology with a needle. Cytological findings from the right nasal cavity were consistent with mast cell tumors (MCTs). Cytological analysis of the left nasal cavity was compatible with dysplasia/cellular reactivity. A heterogeneous population of cells was detected on cytology of the right submandibular lymph node. These findings were consistent with MCT lymph node metastasis. Skull radiography showed an increase in both opacity and soft tissue extension, surpassing the palate, from the canine tooth through the caudal region of the maxillary sinuses to the last molar, without bone destruction. The dog was then admitted for an abdominal ultrasound, which showed no changes in the spleen or liver. The leukocyte count showed mild lymphopenia and the presence of reactive lymphocytes. Through the buffy coat, the presence of rare round cells, compatible with circulating mast cells, was detected. Due to the biological behavior of the neoplasm and its anatomical location, the established therapy was based on the use of vinblastine and prednisolone. The patient did not show any clinical improvements. In a joint decision with the patient's guardian, the dog was euthanized. Discussion: Intranasal MCTs commonly present progressive and intermittent unilateral epitaxis, mucopurulent nasal discharge, dyspnea, and ocular discharge. Several anatomical sites were associated with more aggressive neoplastic phenotypes; those with an unfavorable prognosis were mainly those present in the oral and intranasal mucosa. Cytopathological examination is considered a highly sensitive method for the diagnosis of MCTs. Metastases are present in more than 90% of mucosal MCTs, usually affecting regional lymph nodes and associated with a poor prognosis. Radiography is considered a useful test in determining the size and location of tumors in the nasal cavity. Chemotherapy plays an important role in the treatment, especially in cases like the one described in this report, in which surgical excision is not possible due to the anatomical location of the neoplasm. Intranasal MCTs are uncommon in dogs. In this case, he presented aggressive, metastatic behavior and a poor response to antineoplastic therapy. Furthermore, due to the location of these tumors, they may be clinically similar to a number of other upper respiratory tract diseases, posing a diagnostic challenge. Therefore, it is essential that the search for differential diagnoses be carried out through auxiliary tests, such as cytology and imaging.

Cytological grading of canine mast cell tumors: correlation with histologic grading and survival time / Graduação citológica de mastocitomas caninos: correlação com graduação histológica e sobrevida

ABSTRACT: Mast cell tumors are one of the most common neoplasia in dogs and cytopathology and/or histopathology examinations are used for diagnosis. Histologic grading is considered the gold standard test to predict the prognosis of this neoplasia. However, studies have been conducted using the cytological grading system to provide similar information in a faster, less invasive, and more accessible way. This study aimed to investigate cytological graduation and correlate it with histological grading and the survival time of dogs diagnosed with cutaneous mast cell tumors at the Veterinary Hospital of "Universidade Federal de Uberlândia" over five years. For that, cytological and histological slides from 72 animals were reviewed. The statistical methods used were the kappa test for agreement between grading systems, the Kaplan-Meier for survival time, Cox regression for comparison of cytological and histological grades and survival time. The cytological grading when compared to the two-tier histologic grading, high and low grades, had a moderate agreement (kappa 0.566). When the correlation between survival time and the cytological grade was evaluated, there was a higher death rate in the group with high-grade mast cell tumors compared to low grade, pointing to a correlation between survival time and cytological grade (p=0.009). In conclusion, the cytological grade is useful to treatment planning and providing prognostic information that precedes tumor removal, showing a good correlation with the two-tier histologic grading and with the survival time of the animals.

RESUMO: O mastocitoma é uma das neoplasias cutâneas mais comum nos cães e os exames citopatológicos e/ou histopatológicos são utilizados para diagnóstico. A graduação histológica é considerada padrão ouro para prever o prognóstico dessa neoplasia. Contudo, estudos têm sido realizados visando utilizar graduação citológica para fornecer informações semelhantes de maneira rápida, menos invasiva e mais acessível. Esse trabalho objetivou realizar graduação citológica e correlacionar com as graduações histológicas e com a sobrevida de cães diagnosticados com mastocitoma cutâneo no Hospital Veterinário da Universidade Federal de Uberlândia durante 5 anos. Para isso, lâminas de citologia e histologia de mastocitomas de 72 animais foram revisadas. Os métodos estatísticos utilizados foram teste kappa para concordância entre os sistemas de graduação, método Kaplan-Meier para tempo de sobrevida dos animais, e análise pela regressão de Cox para comparação do grau citológico e grau histológico e o tempo de sobrevida global. A graduação citológica quando comparada com a histológica de dois níveis, alto grau e baixo grau, obteve uma concordância moderada (kappa 0,566). Na avaliação da correlação entre sobrevida e grau citológico, houve maior taxa de óbito no grupo de cães com mastocitoma de alto grau, comparado aos de baixo grau, sendo observada correlação entre a sobrevida e o grau citológico (p=0,009). Esse estudo concluiu que o grau citológico é útil para o planejamento do tratamento e para fornecer informações prognósticas que antecedem a exérese do tumor, tendo boa correlação com a graduação histológica de dois níveis e com a sobrevida dos animais.

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.

Tumor venéreo transmissível canino em laringe com metástase pulmonar / Canine transmissible venereal tumor in the larynx with pulmonary metastasis

Background: Canine transmissible venereal tumor (TVT) is one of the most common canine neoplasms in Brazil. Lesions develop mainly in the genital tissue and less frequently in other areas, in the extragenital form. Metastasis is rare, and the disease progression depends on the patient’s immune status. The treatment of choice is chemotherapy with vincristine sulfate, considered an effective and safe modality. The present work describes the first case of extragenital TVT in the larynx with pulmonary metastasis at the time of diagnosis. Case: An approximately 4-month-old mixed-breed bitch was attended manifesting acute clinical respiratory signs. The patient had been rescued from the street 2 months beforehand. Physical examination revealed pale mucous membranes and crackling pulmonary auscultation. Thoracic radiography was performed in 3 projections, showing multiple nodules in the lung parenchyma, followed by cytopathological examination using fine needle puncture guided by thoracic ultrasound, confirming the diagnosis of TVT. Considering the cytological finding and the absence of primary tumor lesions in the genital, oral, cutaneous or nasal regions, endoscopy was performed in order to locate a possible primary focus. The exam revealed a small erythematous tumor with smooth and regular surface, measuring approximately 2.5 cm, located in the larynx, between the arytenoid cartilages. Chemotherapy was performed with vincristine sulfate with radiographic follow-up throughout the treatment. Full remission of the pulmonary and laryngeal nodules was achieved at the end of the protocol. The animal remained in complete remission for a period of 2 years. Discussion: TVT is more frequently observed in animals of active reproductive age, and rarely in animals under 1 year of age, as in the case...

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.

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)

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)

Atypical transmissible venereal tumor in dogs

Background: The Transmissible Venereal Tumor (TVT), classified as a round cell tumor, is considered one of the oldestexisting tumors. It affects dogs all over the world and has a contagious characteristic. Despite the good response to clinicaltreatment in most cases, it can sometimes have non-classical presentations and even different behavior. Thus, the presentstudy aims to report 3 cases of atypical TVT treated at the Veterinary Medical Teaching Hospital of the State University ofMaringá (UEM) in Umuarama, Paraná, aiming to describe the epidemiology and clinical-pathological aspects, focusingon the diagnostic method used, the treatment of choice and the clinical follow-up of each case.Cases: Case records of 3 intact male mongrel dogs with atypical Transmissible Venereal Tumor (case 1: intranasal; case2: intra-abdominal and case 3: cutaneous with lymph node metastasis) were reviewed regarding history, clinical signs,duration of clinical signs, examination findings, results and findings of complementary exams (hematological, biochemical,radiographic, ultrasonographic and cytological), treatment, follow-up and final result. Case 1: had an ulcerated mass in thenasal plane causing significant airway obstruction and respiratory difficulty. Case 2: had a lesion in a typical location (penilemucosa in the glans area) but with a large intra-abdominal mass in the lumbar paravertebral region, causing compressionof important structures. Case 3: on the other hand, had cutaneous TVT with several ulcerated plaque lesions all over theskin, in addition to popliteal lymph node enlargement due to metastasis later confirmed by microscopy. All dogs reportedwere mixed breed, intact males with free access to the street. Despite...

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.

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.

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.

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.

Pólipo fibroepitelial atípico em córnea de um cão Lhasa Apso / Atypical fibroepithelial polyp in the cornea of a Lhasa Apso dog

Background: Fibroepithelial polyps are benign tumors of mesenchymal and ectodermal origin. Regarding the localization related to the cutaneous region, they may affect the eyelid and periocular area. In veterinary medicine, polyps located in the urethra of dogs and monkeys, vagina of bitches and on the skin have been described. Fibroepithelial polyps may present as single to multiple nodules, exophytic to pedunculated, usually arising on a smooth surface of a common base. The aim of this paper is to describe the ocular and histopathological changes of a corneal fibroepithelial polyp of recurrent character in a dog. Case: A 20-year-old Lhasa Apso dog, with a history of progressive corneal neoformation in the right eye for 4 months. Patient was submitted to routine ophthalmic evaluation. At biomicroscopy, a discrete mucopurulent discharge was observed in the nasal corner, a nodule in the lower eyelid (± 3 mm), moderate conjunctival hyperemia, vascularization and corneal edema between 12 and 5 h, presence of a pinkish proliferative mass in 3 h, affecting the anterior stroma and opacity of the lens, Schirmer's Tear Test (STT) 20 mm/min and intraocular pressure (IOP) 10 mm/Hg. In the left eye, the STT and IOP were within normal range (17 mm/min and 11 mg/Hg, respectively) and at biomicroscopy only lens opacity was observed. Given the presence of the neoformation in the cornea, the patient underwent lamellar keratectomy to excise the mass and third eyelid flap. The tissue was then submitted to histopathology. The histopathological examination showed a proliferation of fibrous component with areas presenting reactive fibroblasts, with acidophilic cytoplasm and with little volume and slight neovascularization, presence of hyperplasia of the lining epithelium and cells with round to oval nuclei, with inconspicuous nucleoli, compatible with fibroepithelial polyp, without evidence of malignancy. After 18 months, the patient presented recurrence of the condition with a history of slow evolution (about ten months). The ophthalmic evaluation showed lesions very similar to the initial one, describing a recurrence of the lesion. Discussion: Corneal neoplasms are uncommon in dogs. The clinical findings in patients with ocular neoplasms include irregular to nodular masses, gray to reddish in color, and typically associated with a vascular supply. These features are related to the type of tumor and its degree of evolution. There are reports in the literature of ocular neoplasms such as squamous cell carcinoma, papilloma, melanocytoma, fibrosarcoma, hemangiosarcoma, melanoma, lymphoma. Related to fibroepithelial polyp with ocular involvement, there are rare reports in human literature and none in veterinary medicine. There is a human description of the presence of a polyp affecting the cornea associated with a corneal dermoid and e other cases of polyps of conjunctival origin. As far as treatment is concerned, the polyp should be surgically removed because of the possibility of recurrence, tissue metaplasia, or even transformation into a malignant tumor, as seen in the case reported here, in which even with surgical removal there was recurrence and metaplasia of the cells. Based on the histopathological findings, it can be concluded that this is a fibroepithelial polyp with a recidivating characteristic, not well described in the veterinary literature, with an atypical presentation affecting the cornea.

Empiema epidural espinhal em gato com suspeita de linfoma em canal vertebral / Spinal epidural empyema in a cat with suspect of spinal canal lymphoma

Background: Spinal epidural empyema (SEE) is a rare disease in cats that has been described as a cause of severe compressive myelopathy. It is characterized by accumulation of purulent exudate in the form of an abscess in the epidural space. Neurological signs range from spinal hyperesthesia to rapidly progressive paraplegia and may be associated with systemic signs. Spinal lymphoma is the most common neoplasm affecting the central nervous system of cats and can mimic different neoplasms and non-neoplastic diseases, such as SEE. The aim of this study is to report a case of SEE in a cat and highlight the similarities in neurological, laboratory, and imaging findings between this disease and spinal lymphoma. Case: A 8-month-old male neutered mixed-breed cat was referred to the Veterinary Medical Teaching Hospital (HVU) of the UFSM with acute, non-progressive paraplegia. On neurological examination, the patient was paraplegic with no nociception, normal spinal reflexes, increased muscle tone in the pelvic limbs, absence of cutaneous trunci reflex, and spinal hyperesthesia between T13-L1, demonstrating injury in the T3-L3 spinal cord segment. The differential diagnoses included acute spinal cord trauma, neoplasm (lymphoma), and infectious diseases. Hemogram showed lymphocytosis (8062/µL); the biochemical examinations were unremarkable. Tests for antibodies against feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) antigens were negative. Simple radiography, abdominal ultrasonography, and cerebrospinal fluid findings were also normal. Myelography showed left dorsolateral extradural spinal cord compression from T12 to L1. Based on these findings, the presumptive diagnosis was spinal lymphoma and chemotherapy was initiated. After 2 days, the animal began to show hyporexia, adipsia, vomiting, and diarrhea, in addition to an increase in subcutaneous volume in the thoracolumbar region. Antibiotic therapy was initiated; however, the patient died. Necropsy revealed an abscess in the left dorsolateral extradural space at T12-T13 and T13-L1. Bacterial cultures revealed the presence of Neisseria spp. that was resistant to various antibiotics. On the basis of these findings, the animal was diagnosed with SEE. Discussion: This case report aims to inform veterinarians about the diagnosis of SEE. SEE is a rare condition in cats compared to spinal lymphoma; however, their presentation is similar. Even in imaging examinations, such as magnetic resonance imaging, it is not possible to differentiate between these 2 conditions. The evolution of clinical signs made the diagnosis of the present case difficult since it was acute and not progressive. All cases of SEE reported in the literature were progressive, acute, or chronic. Although testing for FeLV was negative, only 56% of cats with spinal lymphoma test positive for this virus. Clinical signs reported by the owner after the start of chemotherapy may be related to adverse effects, such as immunosuppression, which led to worsening of the condition, culminating in the appearance of a subcutaneous abscess. Subsequently, SEE was suspected; however, surgical decompression was not performed as the animal died soon after. The authors of this report reinforce the need for a definitive and non-presumptive diagnosis of spinal lymphoma to initiate chemotherapy because it mimics different neoplasms and non-neoplastic diseases, such as SEE. Surgical removal of the compressive mass in the spinal cord and histopathological analyses are necessary.