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 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.

Avaliação morfológica e morfométrica do útero de camundongos fêmeas após uso de extrato de graviola / Morphological and morphometric evaluation of femal e mice uterus after using soursop extract

O presente estudo teve como objetivo avaliar o efeito do extrato de Annona muricata no útero de camundongos fêmeas por meio de análises macro e microscópicas. Vinte camundongos fêmeas foram aleatoriamente distribuídas em quatro grupos: controle (solução salina), ciclofosfamida e extrato de folhas de graviola em duas concentrações diferentes (50 e 100mg/kg). Após sete dias de experimento, as fêmeas foram eutanasiadas e seus úteros coletados e submetidos a análise macroscópica, seguida de processamento histológico para análises morfológicas e morfométricas das camadas do útero e das glândulas endometriais. As características macroscópicas do útero foram mantidas em todos os grupos avaliados. Microscopicamente, não foram identificadas alterações patológicas nas células uterinas. No entanto, houve um aumento significativo na camada do miométrio após o tratamento com ciclofosfamida (p<0,05). O diâmetro interno das glândulas endometriais foi significativamente menor em ambos os grupos tratados com extrato de A. muricata quando comparados ao grupo controle (p<0,05), enquanto o diâmetro total das glândulas foi significativamente menor somente na maior concentração de extrato de A. muricata quando comparado ao grupo controle (p<0,05). A administração do extrato de folhas de A. muricata não causou alterações morfológicas ao útero. Desta forma, o extrato não apresentou toxicidade uterina nas condições avaliadas.

O presente estudo teve como objetivo avaliar o efeito do extrato de Annona muricata no útero de camundongos fêmeas por meio de análises macro e microscópicas. Vinte camundongos fêmeas foram aleatoriamente distribuídas em quatro grupos: controle (solução salina), ciclofosfamida e extrato de folhas de graviola em duas concentrações diferentes (50 e 100mg/kg). Após sete dias de experimento, as fêmeas foram eutanasiadas e seus úteros coletados e submetidos a análise macroscópica, seguida de processamento histológico para análises morfológicas e morfométricas das camadas do útero e das glândulas endometriais. As características macroscópicas do útero foram mantidas em todos os grupos avaliados. Microscopicamente, não foram identificadas alterações patológicas nas células uterinas. No entanto, houve um aumento significativo na camada do miométrio após o tratamento com ciclofosfamida (p<0,05). O diâmetro interno das glândulas endometriais foi significativamente menor em ambos os grupos tratados com extrato de A. muricata quando comparados ao grupo controle (p<0,05), enquanto o diâmetro total das glândulas foi significativamente menor somente na maior concentração de extrato de A. muricata quando comparado ao grupo controle (p<0,05). A administração do extrato de folhas de A. muricata não causou alterações morfológicas ao útero. Desta forma, o extrato não apresentou toxicidade uterina nas condições avaliadas.

Linfoma mediastinal em gato com vírus da leucemia felina / Mediastinal lymphoma in a cat with feline leukemia virus

Background: Mediastinal lymphoma occurs at a high incidence in cats positive for feline leukemia virus (FeLV). It is a malignant lymphocytic neoplasm that may trigger clinical signs such as dyspnea, apathy, regurgitation, and weight loss. The objective of this work is to report a case of mediastinal lymphoma associated with FeLV in a cat, and describe the clinical, pathological, diagnostic, and therapeutic aspects that can help the diagnosis and treatment of this disease. Case: A 3-year-old male neutered cat weighing 4.6 kg, positive for FeLV, and with a history of dyspnea and hyporexia was referred to a private veterinary clinic in the city of Caxias do Sul, RS, Brazil. The only alteration found at the clinical examination was a muffled sound during lung auscultation. Radiographs of the thorax revealed the presence of pleural effusion; after drainage of the fluid, a mass located in the mediastinal area became radiographically observable. An analysis of the effusion fluid showed high cellularity characterized by a markedly pleomorphic population of individual round cells consistent with lymphocytes. Small lymphocytes with a high nucleus:cytoplasm ratio, round nucleus, condensed chromatin, and inconspicuous nucleoli were observed, along with medium and large lymphocytes. The medium and large lymphocytes were characterized by a variably increased nucleus:cytoplasm ratio and a scant to moderate cytoplasm exhibiting moderate to intense basophilia and, occasionally, vacuoles. The nuclei were round, idented, or irregular; most of them were located eccentrically and contained coarse to finely granular chromatin. Nucleoli varied from single to multiple, round to angular, and central to peripheral and prominent. Macronucleoli and marked anisonucleosis were also observed, as well as binucleated cells and rare multinucleated cells. The conclusion was that it was a case of neoplastic effusion caused by a lymphoma. After an appointment with an oncologist, a chemotherapy protocol was established. The treatment of choice was CHOP, a combination of cyclophosphamide (20 mg/kg orally), doxorubicin (1 mg/kg intravenously), vincristine (0.5 mg/m2 intravenously), and prednisolone with a regressive dose starting at 2 mg/kg. The patient underwent 4 rounds of chemotherapy, and received a maintenance treatment thereafter. The patient's condition remained stable for 390 days without relevant clinical or hematological alterations. Discussion: The diagnosis of mediastinal lymphoma was established by associating clinical finings, laboratory exams, and radiographic findings. Exams of utmost importance to reach this diagnosis were the thoracic radiography, which revealed the presence of a mass in the thorax, and the cytopathological analysis of the effusion fluid, as round cell neoplasms are easily dissociated. Young cats are the group most affected by FeLV, and mediastinal lymphoma is considered the most prevalent type of lymphoma in this species. The most common clinical sign is dyspnea; however, other signs such as apathy, weight loss, regurgitation (due to pressure on the esophagus), and Horner's syndrome (owing to pressure on the thoracic sympathetic innervation) may also occur. This disease is treated with chemotherapy, with CHOP frequently used as the chemotherapeutic protocol. The good therapeutic response for a longer time than the average estimated by studies on the prognostic of this disease indicates that a correct diagnosis along with an assertive approach and the cooperation of the tutor are essential in cases of mediastinal lymphoma.

Carcinoma uretral primário em uma cadela - tratamento multimodal / Primary urethral carcinoma in a bitch - multimodal treatment

Background: Urethral tumors are uncommon in canines, represented predominantly by transitional cell carcinoma, marked by aggressive behavior associated with short life expectancy. Definitive diagnosis is achieved by histopathological analysis. Surgery associated with chemotherapy is the main therapeutic alternative. The aim of this paper is to report a case of primary transitional cell carcinoma of the urethra in a bitch, submitted to surgical treatment associated with conventional adjuvant chemotherapy and metronomic chemotherapy, achieving survival of 21 months, to date. Case: A 12-year-old bitch mixed breed was admitted at the Veterinary Hospital of Federal Rural University of Rio de Janeiro (UFRRJ), manifesting hematuria and urinary incontinence for one month. Physical examination indicated that vital parameters were within normal limits. Laboratory tests of blood count and serum biochemistry, urinalysis, culture, urinary antibiogram, and abdominal ultrasound were performed. The ultrasound image suggested a neoplastic urethral process. Because of the suspicion of neoplasm, a thoracic X-ray was performed, showing no evidence of metastasis. Computed tomography (CT) of the abdominal region was performed, revealing an expansive lesion in the urethra with loss of definition of the walls and urethral lumen extending to the level of the pelvic floor, measuring about 2.9 x 1.4 x 1.2 cm. After preanesthetic exams, the animal underwent resection and surgical anastomosis of the affected urethral region. The sectioned tissue was sent for histopathological analysis, with diagnosis of transitional cell carcinoma. Adjuvant chemotherapy was performed using carboplatin at a dose of 250 mg/m², intravenously, every 21 days for 6 sessions. After completing the protocol, abdominal ultrasonography was performed again, which showed a cicatricial process in the urethral region of the surgical excision, with no sign of tumor recurrence. A metronomic chemotherapy protocol was then started with cyclophosphamide at a dose of 15 mg/m², daily for 6 months, with periodic oncological follow-up. At the end of the period, the animal remained under periodic follow-up with ultrasound exams performed at 2-month intervals, and has been free from recurrence for 21 months until now. Discussion: Urethral neoplasms account for 0.5 - 2% of all canine tumors, and are represented mostly by transitional cell carcinomas. Clinical signs of urinary obstruction and hematuria are the most common, as reported in the patient in question. The definitive diagnosis is by histopathological examination. However, imaging tests such as computed tomography are important in the initial investigation and surgical planning. The indicated treatment is surgical resection of the mass with subsequent adjuvant chemotherapy or radiotherapy. The chemotherapy protocol associating cisplatin and piroxicam can achieve remission rates of 70%, but this association has a high nephrotoxic effect. In the present case, cisplatin was replaced by carboplatin in order to reduce the nephrotoxic effects of chemotherapy. The metronomic protocol using cyclophosphamide was used as maintenance therapy, at the end of the conventional chemotherapy protocol. Survival achieved was longer than that described in the literature in cases of transitional cell carcinomas in the urethral region. Therefore, multimodal therapy using surgery associated with conventional and metronomic chemotherapy, is an option in canines with urethral carcinoma.

Effects of ß-glucan from S. cerevisiae on the expression of Casp9, Ccna2 and Sod1 genes in MCF-7 cells

ß-Glucans (ßG) are polysaccharides widely distributed in nature with chemopreventive properties. The aim of this study was to investigate the effects of ßG and the combined treatment with doxorubicin (Dox) on cell viability and mRNA levels of genes involved in cell cycle, apoptosis and antioxidant response. ßG was not cytotoxic. The mRNA levels of CCNA2of cells exposed to ß-glucan was upregulated and the exposure to Dox decreased the expression, while the combination led to an upregulation. Modulation of mRNA levels of CASP9suggest that ßG could inhibit promotion and progression steps of carcinogenesis, eliminatingneoplastic cells. The upregulation of CCNA2gene in combined treatment could be occurred due to ability of ßG in restoring the cell cycle distribution pattern after treatment with Dox. The upregulation of SOD1suggests that ßG can enhance the intracellular antioxidant defense, reducing the levels of superoxide dismutase induced by Dox. This response could reduce oxidative damage and attenuate tissue damage during chemotherapeutic treatment. Our data suggest that the drug combination may be less effective in killing tumor cells than the treatment with Dox alone. Thus, future studies should carefully consider this effect on indication of ßG during chemotherapy.Keywords:caspase-9; cyclin A2; superoxide dismutase 1; cell cycle; antioxidant.Received on July 2, 2020.Accepted on February 7, 2022.IntroductionGlucans are polysaccharides widely distributed in nature and oftenstudied due to chemopreventive properties. They are constituent of the cell wall of plants (oats and barley), algae, bacteria and fungi. ß-glucans (ßG)have a common structure comprising a main chain of ß-(1,3) and/or ß-(1,4) D-glucopyranosyl unit and they differ in length and branching structures. ßG of Saccharomyces cerevisiaehave 1→6 side branches while those of bacteria have 1→4 side branches (Chan, Chan, & Sze, 2009). ßGcan prevent DNA damage induced by chemical and physical agents (Ghavami,Goliaei, Taghizadeh, & Nikoofar, 2014). Some authors showed its significant efficacy in preventing mutagenic effects caused by doxorubicin, cyclophosphamide and cisplatin (Tohamy, El-Ghor, El-Nahas, & Noshy, 2003), methyl methanesulfonate (Oliveira et al., 2007)and hydrogen peroxide (Slamenová, 2003). Moreover, some studies have related the antioxidant ability of ßGagainst reactive free radicals formed by endogenous metabolic processes or exogenous chemicals (Tsiapali et al., 2001; Slamenová,2003; Sener, Eksioglu-Demiralp, Cetiner, Ercan, & Yegen, 2006; Guerra Dore et al., 2007; Kofuji et al., 2012; Lei et al., 2015). Yeast-derived ßGhave modulating action of humoral and cellular immune responses (Vetvicka et al., 2007).This activity provides protection to the organism against infections and cancer development (Samuelsen, Schrezenmeir, & Knutsen, 2014; Roudbary, Daneshmand, Hajimorad, Roudbarmohammadip, & Hassan, 2015). Despite postulated modes of action by which ß-glucan works are lacking information about the molecular mechanisms involved in the chemopreventive activity of this polysaccharide. In addition, compounds with chemopreventive properties can contribute to reduce side effects and toxicity during the chemotherapeutic treatment. Therefore, the aim of this study was to investigate the effects of ßG and the combined treatment with doxorubicin (Dox) on the expression of genes related with apoptosis (CASP9), cell cycle control (CCNA2)and antioxidant defense (SOD1)in human breast cancer MCF-7 cells. Doxorubicin (Dox) was chosen because it is one of the most used chemotherapeutic agent for cancer treatment. The limitation on the use of Dox in cancer treatment is the lack of selectivity against cancer cells and, consequently, its toxicity to patients.(AU)

Acute phase protein and vitamin D concentration in dogs with multicentric lymphoma / Concentração de proteínas de fase aguda e vitamina D em cães com linfoma multicêntrico

This study aimed to evaluate the serum concentration of vitamin D (25-Hydroxyvitamin D) and acute phase proteins (APPs; alpha-1 acid glycoprotein, haptoglobin, transferrin, ceruloplasmin, albumin, IgA, IgG and alpha-1 - antitrypsin) as potential biomarkers for prognostic and therapy response in dogs with multicentric lymphoma submitted to the CHOP (Cyclophosphamide, Doxorubicin, Vincristine and Prednisone) chemotherapy protocol. Thirteen dogs with multicentric lymphoma classified as high grade by cytology were included in the treatment group (GL), while ten healthy dogs were included in the control group (GC). Serum was collected in the weeks T0, T5 and T10 of CHOP chemotherapy protocol, for the GL group, and in a single collection, for the GC group. All the collected samples were evaluated for the APPs and vitamin D concentrations through electrophoresis and chemiluminescence methods, respectively. Diagnostic and staging tests were performed for all the dogs in the GL group, and included cytopathology, histopathology and immunohistochemistry of the affected lymph node. Of these dogs, 9 achieved a complete response and 4 a partial response to the treatment. Data analysis was performed with the R software. The results demonstrated that serum concentrations of IgA, haptoglobin and α1-acid glycoprotein were significantly different between the groups and also between the different chemotherapy times analyzed (p<0.05), indicating that these proteins can be considered as sensitive biomarkers for lymphoma in dogs. Furthermore, the α1-acid glycoprotein showed prognostic value for the disease, with 63% specificity. However, vitamin D concentration was not correlated with prognosis of the dogs with lymphoma.

Objetivou-se caracterizar a concentração sérica da vitamina D e das PFAs (Proteínas de Fase Aguda) (alfa-1 glicoproteína ácida, haptoglobina, transferrina, ceruloplasmina, albumina, IgA, IgG e alfa-1 ­ antitripsina) em cães com linfoma multicêntrico, submetidos ao tratamento quimioterápico com protocolo CHOP (Ciclofosfamida, Doxorrubicina, Vincristina e Prednisona), determinando o valor prognóstico desses marcadores para a doença. Foram avaliadas as concentrações séricas das PFAs, através do método da eletroforese e as concentrações da vitamina D, através da quimioluminescência em dois grupos experimentais, um grupo de 13 cães com linfoma multicêntrico classificados como alto grau pela citologia (GL) durante as semanas T0, T5 e T10 do tratamento com protocolo quimioterápico antineoplásico e em um grupo de 10 animais saudáveis para compor o grupo controle (GC), em coleta única. Para isso, foi realizado o diagnóstico, estadiamento e avaliação de resposta terapêutica dos 13 pacientes com linfoma multicêntrico através de técnicas de citopatologia, histopatologia, imuno-histoquímica do linfonodo periférico acometido. Foi observado que 9 pacientes tiveram resposta completa e 4 pacientes tiveram resposta parcial ao tratamento. Os dados foram analisados através do software R. Os resultados indicam que as diferenças entre as variáveis IgA, haptoglobina e α1-glicoproteína ácida foram significativas entre os grupos, e entre os diferentes momentos da quimioterapia (p< 0,05), indicando que podem ser marcadores sensíveis ao linfoma em cães. A α1-glicoproteína ácida apresentou valor prognóstico para o linfoma, com 63% de especificidade. Porém a vitamina D não apresentou valor prognóstico para o linfoma multicêntrico em cães.

Surgical treatment associated with adjuvant chemotherapy with cyclophosphamide and piroxicam in cervical sarcoma of a blue-fronted amazon (Amazona aestiva): case report / Tratamento cirúrgico com uso de quimioterapia adjuvante com ciclofosfamida e piroxicam em sarcoma cervical de um papagaio-verdadeiro (Amazona aestiva): relato de caso

The occurrence of neoplasms in birds is still unknown, with the literature based mainly on scarce reports, in this context, data about epidemiology in specific species are almost nonexistent. Sarcomas are malignant mesenchymal origin neoplasms, which can develop from different tissues, such as adipose, cartilage, bone, among others. The occurrence of sarcomas in birds has been previously described, with different therapeutic approaches. The present report describes the clinical approach in a blue-fronted amazon (Amazona aestiva) diagnosed with a soft tissue sarcoma in the dorsal cervical region, with surgical excision associated with a metronomic chemotherapy protocol as an adjuvant. The therapeutic combination proved to be effective in controlling the disease, guaranteeing important survival, with clinical absence of side effects.

A ocorrência das neoplasias em aves ainda é desconhecida, com a literatura se baseando principalmente em relatos escassos, nesse contexto, dados acerca de epidemiologia em espécies específicas são quase inexistentes. Os sarcomas são neo-plasias malignas de origem mesenquimal, podendo se desenvolver a partir de tecidos diversos, como adiposo, cartilaginoso, ósseo, dentre outros. A ocorrência de sarcomas em aves já foi previamente descrita, com diferentes abordagens terapêuticas. O presente relato descreve a abordagem clínica em um papagaio-verdadeiro (Amazona aestiva) diagnosticado com um sarcoma de tecidos moles em região cervical dorsal, sendo realizada a exérese cirúrgica associada a protocolo quimioterápico metronô-mico em caráter adjuvante. A combinação terapêutica se mostrou eficaz no controle da doença, garantindo sobrevida impor-tante, na ausência clínica de efeitos colaterais.

Surgical treatment associated with adjuvant chemotherapy with cyclophosphamide and piroxicam in cervical sarcoma of a blue-fronted amazon (Amazona aestiva): case report / Tratamento cirúrgico com uso de quimioterapia adjuvante com ciclofosfamida e piroxicam em sarcoma cervical de um papagaio-verdadeiro (Amazona aestiva): relato de caso

The occurrence of neoplasms in birds is still unknown, with the literature based mainly on scarce reports, in this context, data about epidemiology in specific species are almost nonexistent. Sarcomas are malignant mesenchymal origin neoplasms, which can develop from different tissues, such as adipose, cartilage, bone, among others. The occurrence of sarcomas in birds has been previously described, with different therapeutic approaches. The present report describes the clinical approach in a blue-fronted amazon (Amazona aestiva) diagnosed with a soft tissue sarcoma in the dorsal cervical region, with surgical excision associated with a metronomic chemotherapy protocol as an adjuvant. The therapeutic combination proved to be effective in controlling the disease, guaranteeing important survival, with clinical absence of side effects.(AU)

A ocorrência das neoplasias em aves ainda é desconhecida, com a literatura se baseando principalmente em relatos escassos, nesse contexto, dados acerca de epidemiologia em espécies específicas são quase inexistentes. Os sarcomas são neo-plasias malignas de origem mesenquimal, podendo se desenvolver a partir de tecidos diversos, como adiposo, cartilaginoso, ósseo, dentre outros. A ocorrência de sarcomas em aves já foi previamente descrita, com diferentes abordagens terapêuticas. O presente relato descreve a abordagem clínica em um papagaio-verdadeiro (Amazona aestiva) diagnosticado com um sarcoma de tecidos moles em região cervical dorsal, sendo realizada a exérese cirúrgica associada a protocolo quimioterápico metronô-mico em caráter adjuvante. A combinação terapêutica se mostrou eficaz no controle da doença, garantindo sobrevida impor-tante, na ausência clínica de efeitos colaterais.(AU)

Characterization and assessment of the genotoxicity and biocompatibility of poly (hydroxybutyrate) and norbixin membranes

Purpose To synthesize and characterize poly(hydroxybutyrate) (PHB) and norbixin membranes to evaluate them for genotoxicity in rats and wound healing in mice by histological staining. Methods For the evaluation of genotoxicity, male rats ( Rattus novegicus ) were divided into three groups (n= 5): 5% PHB/Norbixin membrane introduced into the peritoneum by laparotomy; B negative control; C positive control (intraperitoneal dose of cyclophosphamide 50 mg/kg). For the evaluation of biocompatibilty, a cutaneous wound was induced on the back of males mice ( Mus musculus ) divided into two experimental treatment groups: control and membrane that underwent euthanasia after 7 and 14 days treatment. Statistical analysis ware made by One Way Anova post hoc Tukey Test (p<0.05). Results Regarding the incidence of polychromatic erythrocytes, there was no difference between negative control and 5% PHB/Norbixin membrane; however, when compared to the positive control represented by cyclophosphamide, there was a significant difference (p <0.001). As for DNA damage, the changes induced in the first 4h were repaired in 24h. In addition, the membrane was effective in abbreviating the inflammatory process and served as a scaffold due to the stimulus to reepithelialization mainly on the 7 days of treatment. Conclusion The non-genotoxic PHB/Norbixin 5% membrane presented promising results that suggest its effectiveness as a guide for tissue regeneration given its biocompatibility.(AU)

Clinical, histopathological and immunohistochemical features ofa thymoma in a domestic rabbit (Oryctolagus cuniculus): casereport

Thymoma is a neoplasm originating from epithelial cells of the thymus. It represents the most common tumor in the mediastinal region of rabbits, followed by lymphoma. This study aims to report a case of post mortem diagnosis of thymoma in a rabbit (Oryctolagus cuniculus), with the purpose to contribute to the understanding of this disease and its diagnosis in this specie. A six-year-old male mixed breed pet rabbit (O. cuniculus), weighing 2.3 kg, was referred to necropsy exam. The previous clinical history included prostration, lethargy, weight loss, dysorexia and respiratory distress, evidenced mainly on the expiratory phase. Radiographs revealed pleural effusion and the presence of a mass involving the cranial and middle mediastinum, confirmed by ultrasound. In the cytological examination, it was diagnosed as a low-gradelymphoma and chemotherapy was performed with COP (cyclophosphamide, vincristine Oncovin®, prednisolone). However, after 145 days, euthanasia was performed. At necropsy, a well delimited mass was observed in the mediastinal region, adhered to the pleura, with firm consistency and pale coloration. Histopathological analysis of the mass showed the proliferation of epithelial neoplastics cells, arranged in trabeculas and with infiltration of small lymphocytes. The immunohistochemical findings included cytoplasmic immunolabeling for cytokeratin AE1/AE3 in 90% of epithelial neoplastics cells, while CD3 was evidenced in a small number of lymphocytes (T-lymphocytes) and CD79a in Blymphocytes localized on the neoplasia periphery. The growth fraction was estimated at 30% by Ki-67. According to the histopathological criteria for thymoma classification proposed by the World Health Organization, 2015, it was made the diagnosis of lymphocyte-rich predominantly cortical thymoma (B1 type).(AU)

Clinical, histopathological and immunohistochemical features ofa thymoma in a domestic rabbit (Oryctolagus cuniculus): casereport

Thymoma is a neoplasm originating from epithelial cells of the thymus. It represents the most common tumor in the mediastinal region of rabbits, followed by lymphoma. This study aims to report a case of post mortem diagnosis of thymoma in a rabbit (Oryctolagus cuniculus), with the purpose to contribute to the understanding of this disease and its diagnosis in this specie. A six-year-old male mixed breed pet rabbit (O. cuniculus), weighing 2.3 kg, was referred to necropsy exam. The previous clinical history included prostration, lethargy, weight loss, dysorexia and respiratory distress, evidenced mainly on the expiratory phase. Radiographs revealed pleural effusion and the presence of a mass involving the cranial and middle mediastinum, confirmed by ultrasound. In the cytological examination, it was diagnosed as a low-gradelymphoma and chemotherapy was performed with COP (cyclophosphamide, vincristine – Oncovin®, prednisolone). However, after 145 days, euthanasia was performed. At necropsy, a well delimited mass was observed in the mediastinal region, adhered to the pleura, with firm consistency and pale coloration. Histopathological analysis of the mass showed the proliferation of epithelial neoplastics cells, arranged in trabeculas and with infiltration of small lymphocytes. The immunohistochemical findings included cytoplasmic immunolabeling for cytokeratin AE1/AE3 in 90% of epithelial neoplastics cells, while CD3 was evidenced in a small number of lymphocytes (T-lymphocytes) and CD79a in Blymphocytes localized on the neoplasia periphery. The growth fraction was estimated at 30% by Ki-67. According to the histopathological criteria for thymoma classification proposed by the World Health Organization, 2015, it was made the diagnosis of lymphocyte-rich predominantly cortical thymoma (B1 type).

Modified comet assay with Giemsa staining: a suitable method for assessing genotoxicity in rats / Ensaio cometa modificado com coloração de Giemsa: um método adequado para avaliar a genotoxicidade em ratos

The present study tested a comet assay that was modified for compatibility with Giemsa staining to assess the drug genotoxicity in the peripheral blood of rats. We analysed the peripheral blood of 16 female Wistar rats (N=8 rats/group) from a control group and from a group that was treated with an intraperitoneal injection of 50mg cyclophosphamide/kg. The comet assay was carried out with modifications of the blood volume and immersion time in the lysing solution and different combinations of electrophoresis conditions (running time, voltage and current), to Giemsa staining. The lysing time and electrophoresis conditions allowed for the expression of all classes of DNA damage during the electrophoresis run, and the comets were efficiently stained with Giemsa. The technique showed high reproducibility for the DNA classes. The results demonstrate that the modified comet assay with Giemsa staining can be standardized for routine laboratory procedures using a 20µL blood sample, 3h and 30min immersions in the lysing solution and electrophoresis runs with 23 to 25 V and 310 and 360mA of electrical current. The modified comet assay with Giemsa staining that was described in the present study was standardized to be applied in the laboratory routine.(AU)

O presente estudo testou um ensaio cometa modificado para a coloração de Giemsa para avaliar a genotoxicidade de fármacos no sangue periférico de ratos. Analisou-se o sangue periférico de 16 ratas Wistar (n=8 ratas/grupo) de um grupo controle e de um grupo que foi tratado com uma injeção intraperitoneal de 50mg/kg pv. de ciclofosfamida. O ensaio cometa foi realizado com modificações do volume sanguíneo e do tempo de imersão na solução de lise, bem como com diferentes combinações de condições de eletroforese (tempo de corrida, tensão e corrente), para coloração de Giemsa. O tempo de lise e as condições de eletroforese permitiram a expressão de todas as classes de danos no DNA durante a corrida de eletroforese, e os cometas foram eficientemente corados com Giemsa. A técnica mostrou alta reprodutibilidade para as classes de DNA. Os resultados demonstram que o ensaio cometa modificado com coloração de Giemsa foi padronizado para procedimentos laboratoriais de rotina usando-se uma amostra de sangue de 20µL, 3h30min de imersão na solução de lise e eletroforese com 23 a 25 V e 310 e 360mA. O ensaio cometa modificado com coloração de Giemsa descrito foi padronizado para ser aplicado na rotina laboratorial.(AU)

Modified comet assay with Giemsa staining: a suitable method for assessing genotoxicity in rats / Ensaio cometa modificado com coloração de Giemsa: um método adequado para avaliar a genotoxicidade em ratos

The present study tested a comet assay that was modified for compatibility with Giemsa staining to assess the drug genotoxicity in the peripheral blood of rats. We analysed the peripheral blood of 16 female Wistar rats (N=8 rats/group) from a control group and from a group that was treated with an intraperitoneal injection of 50mg cyclophosphamide/kg. The comet assay was carried out with modifications of the blood volume and immersion time in the lysing solution and different combinations of electrophoresis conditions (running time, voltage and current), to Giemsa staining. The lysing time and electrophoresis conditions allowed for the expression of all classes of DNA damage during the electrophoresis run, and the comets were efficiently stained with Giemsa. The technique showed high reproducibility for the DNA classes. The results demonstrate that the modified comet assay with Giemsa staining can be standardized for routine laboratory procedures using a 20µL blood sample, 3h and 30min immersions in the lysing solution and electrophoresis runs with 23 to 25 V and 310 and 360mA of electrical current. The modified comet assay with Giemsa staining that was described in the present study was standardized to be applied in the laboratory routine.(AU)

O presente estudo testou um ensaio cometa modificado para a coloração de Giemsa para avaliar a genotoxicidade de fármacos no sangue periférico de ratos. Analisou-se o sangue periférico de 16 ratas Wistar (n=8 ratas/grupo) de um grupo controle e de um grupo que foi tratado com uma injeção intraperitoneal de 50mg/kg pv. de ciclofosfamida. O ensaio cometa foi realizado com modificações do volume sanguíneo e do tempo de imersão na solução de lise, bem como com diferentes combinações de condições de eletroforese (tempo de corrida, tensão e corrente), para coloração de Giemsa. O tempo de lise e as condições de eletroforese permitiram a expressão de todas as classes de danos no DNA durante a corrida de eletroforese, e os cometas foram eficientemente corados com Giemsa. A técnica mostrou alta reprodutibilidade para as classes de DNA. Os resultados demonstram que o ensaio cometa modificado com coloração de Giemsa foi padronizado para procedimentos laboratoriais de rotina usando-se uma amostra de sangue de 20µL, 3h30min de imersão na solução de lise e eletroforese com 23 a 25 V e 310 e 360mA. O ensaio cometa modificado com coloração de Giemsa descrito foi padronizado para ser aplicado na rotina laboratorial.(AU)

Gastrointestinal stromal tumor associated with hypertrophic osteopathy in a dog

Background: Gastrointestinal stromal tumor (GIST) is a malignant mesenchymal neoplasm rarely described in the veterinary routine. The aim of this study was to report a case of GIST accompanied by a periosteal reaction, suggestive ofhypertrophic osteopathy, in a dog.Case: An 11-year-old male dog had a history of progressive weight loss, difficulty in locomotion, and dyspnea. During clinical care, increased bone volume was observed. Blood samples were collected for a complete blood count and biochemicalanalysis. The dog also underwent thoracic radiography and abdominal ultrasonography. The test results revealed anemia,leukocytosis, hypocalcemia, hypoalbuminemia, and hypocholesterolemia. The radiographic images of the limbs showeda generalized periosteal reaction, and thoracic radiography indicated changes compatible with mild chronic lung disease.Ultrasonographic findings indicated a neoformation in the intestinal loop of the right mesogastric region and increasedvolume in the left testicle, both of which were indicative of neoplasia. Therefore, the dog was referred for surgery, whereinthe intestinal mass and both testes were removed; the intestinal mass and left testicle were subjected to histopathologicaldiagnosis. The results of the biopsies confirmed that the testicular neoplasm was a seminoma, whereas the intestinal nodulewas compatible with GIST, and immunohistochemical analysis was necessary to confirm the diagnosis. On the basis ofpositive labeling for the antibodies vimentin, desmin, S100, and c-kit, the diagnosis of GIST was confirmed. Therefore,the animal underwent metronomic chemotherapy with 12 mg/m2 cyclophosphamide every 24 h for 3 months, and thereafter every 48 h for 6 months. Moreover, the dog was periodically monitored via imaging (radiography of the anteriorand posterior limbs, abdominal ultrasonography, and computed tomography)...

Gastrointestinal stromal tumor associated with hypertrophic osteopathy in a dog

Background: Gastrointestinal stromal tumor (GIST) is a malignant mesenchymal neoplasm rarely described in the veterinary routine. The aim of this study was to report a case of GIST accompanied by a periosteal reaction, suggestive ofhypertrophic osteopathy, in a dog.Case: An 11-year-old male dog had a history of progressive weight loss, difficulty in locomotion, and dyspnea. During clinical care, increased bone volume was observed. Blood samples were collected for a complete blood count and biochemicalanalysis. The dog also underwent thoracic radiography and abdominal ultrasonography. The test results revealed anemia,leukocytosis, hypocalcemia, hypoalbuminemia, and hypocholesterolemia. The radiographic images of the limbs showeda generalized periosteal reaction, and thoracic radiography indicated changes compatible with mild chronic lung disease.Ultrasonographic findings indicated a neoformation in the intestinal loop of the right mesogastric region and increasedvolume in the left testicle, both of which were indicative of neoplasia. Therefore, the dog was referred for surgery, whereinthe intestinal mass and both testes were removed; the intestinal mass and left testicle were subjected to histopathologicaldiagnosis. The results of the biopsies confirmed that the testicular neoplasm was a seminoma, whereas the intestinal nodulewas compatible with GIST, and immunohistochemical analysis was necessary to confirm the diagnosis. On the basis ofpositive labeling for the antibodies vimentin, desmin, S100, and c-kit, the diagnosis of GIST was confirmed. Therefore,the animal underwent metronomic chemotherapy with 12 mg/m2 cyclophosphamide every 24 h for 3 months, and thereafter every 48 h for 6 months. Moreover, the dog was periodically monitored via imaging (radiography of the anteriorand posterior limbs, abdominal ultrasonography, and computed tomography)...(AU)

Linfocitose extrema associada à leucemia linfoblástica aguda (LLA) de células T em um cão jovem: relato de caso / Extreme lymphocytosis associated with acute T-cell lymphoblastic leukemia (ALL) in a young dog: case report

A leucemia linfoblástica aguda (LLA) é uma enfermidade de origem linfóide e consiste na proliferação de células neoplásicas na medula óssea. O objetivo desse trabalho é relatar o caso de um cão macho, sem raça definida, de apenas um ano de idade, atendido no Hospital Universitário de Medicina Veterinária Prof. Firmino Mársico Filho (HUVET) da Universidade Federal Fluminense (UFF) com queixa principal de inapetência e diarreia há três dias e que foi diagnosticado com essa neoplasia por meio da sintomatologia clínica, resultados do hemograma e do mielograma. O paciente apresentava valores exacerbados de linfócitos (553.094 células/µL), além de anemia, trombocitopenia, hipoalbuminemia e elevação da atividade das enzimas fosfatase alcalina e ALT. Foram observadas manchas de Gümprecht, linfócitos atípicos apresentando anisocitose, anisocariose, intensa basofilia citoplasmática e monócitos ativados. O mielograma apresentou também um aumento de linfócitos e contagem de linfoblastos superior a 30% na medula, confirmando o diagnóstico de leucemia linfoblástica aguda. Ademais, posteriormente, foi realizado exame de Reação em Cadeia de Polimerase (PCR) para rearranjos de receptores de antígenos e foi detectado clonalidade para linfócitos T. O animal foi submetido à quimioterapia (protocolo com ciclofosfamida, vincristina e prednisona) mas não resistiu à gravidade do quadro, vindo a óbito após a primeira sessão, pouco tempo após o diagnóstico.

Acute lymphoblastic leukemia (LLA) is a disease with a lymphoid origin and consists of the proliferation of neoplastic cells in the bone marrow. The aim of this study was to report the case of only one year old mixed breed male dog, attended at the University Hospital of Veterinary Medicine Prof. Firmino Mársico Filho (HUVET) from Universidade Federal Fluminense (UFF), with major complaint of inappetence and diarrhea three days ago and which was diagnosed with this neoplasm through clinical symptoms, complete blood count and myelogram results. The patient had increased values of lymphocytes (553,094 cells/µL), in addition to anemia, thrombocytopenia, hypoalbuminemia and elevated alkaline phosphatase and ALT activities. Gümprecht shadows, atypical lymphocytes presenting anisocytosis, anisocariosis, and severe cytoplasmic basophilia and activated monocytes were observed. Myelogram also showed an increase in lymphocytes and a lymphoblastic count greater than 30% in the marrow, confirming the diagnosis of LLA. In addition, polymerase chain reaction (PCR) for antigen receptor rearrangements was performed and clonality for T lymphocytes was detected. The animal underwent chemotherapy (protocol with cyclophosphamide, vincristine and prednisone), but did not withstand the severity of the disease, coming to death after the first session, shorly after diagnosis.

Linfocitose extrema associada à leucemia linfoblástica aguda (LLA) de células T em um cão jovem: relato de caso / Extreme lymphocytosis associated with acute T-cell lymphoblastic leukemia(ALL) in a young dog: case report

A leucemia linfoblástica aguda (LLA) é uma enfermidade de origem linfóide e consiste na proliferação de células neoplásicas na medula óssea. O objetivo desse trabalho é relatar o caso de um cão macho, sem raça definida, de apenas um ano de idade, atendido no Hospital Universitário de Medicina Veterinária Prof. Firmino Mársico Filho (HUVET) da Universidade Federal Fluminense (UFF) com queixa principal de inapetência e diarreia há três dias e que foi diagnosticado com essa neoplasia por meio da sintomatologia clínica, resultados do hemograma e do mielograma. O paciente apresentava valores exacerbados de linfócitos (553.094 células/µL), além de anemia, trombocitopenia, hipoalbuminemia e elevação da atividade das enzimas fosfatase alcalina e ALT. Foram observadas manchas de Gümprecht, linfócitos atípicos apresentando anisocitose, anisocariose, intensa basofilia citoplasmática e monócitos ativados. O mielograma apresentou também um aumento de linfócitos e contagem de linfoblastos superior a 30% na medula, confirmando o diagnóstico de leucemia linfoblástica aguda. Ademais, posteriormente, foi realizado exame de Reação em Cadeia de Polimerase (PCR) para rearranjos de receptores de antígenos e foi detectado clonalidade para linfócitos T. O animal foi submetido à quimioterapia (protocolo com ciclofosfamida, vincristina e prednisona), mas não resistiu à gravidade do quadro, vindo a óbito após a primeira sessão, pouco tempo após o diagnóstico.(AU)

Acute lymphoblastic leukemia (LLA) is a disease with a lymphoid origin and consists of the proliferation of neoplastic cells in the bone marrow. The aim of this study was to report the case of only one year old mixed breed male dog, attended at the University Hospital of Veterinary Medicine Prof. Firmino Mársico Filho (HUVET) from Universidade Federal Fluminense (UFF), with major complaint of inappetence and diarrhea three days ago and which was diagnosed with this neoplasm through clinical symptoms, complete blood count and myelogram results. The patient had increased values of lymphocytes (553,094 cells/μL), in addition to anemia, thrombocytopenia, hypoalbuminemia and elevated alkaline phosphatase and ALT activities. Gümprecht shadows, atypical lymphocytes presenting anisocytosis, anisocariosis, and severe cytoplasmic basophilia and activated monocytes were observed. Myelogram also showed an increase in lymphocytes and a lymphoblastic count greater than 30% in the marrow, confirming the diagnosis of LLA. In addition, polymerase chain reaction (PCR) for antigen receptor rearrangements was performed and clonality for T lymphocytes was detected. The animal underwent chemotherapy (protocol with cyclophosphamide, vincristine and prednisone), but did not withstand the severity of the disease, coming to death after the first session, shortly after diagnosis.(AU)

Linfocitose extrema associada à leucemia linfoblástica aguda (LLA) de células T em um cão jovem: relato de caso / Extreme lymphocytosis associated with acute T-cell lymphoblastic leukemia(ALL) in a young dog: case report

A leucemia linfoblástica aguda (LLA) é uma enfermidade de origem linfóide e consiste na proliferação de células neoplásicas na medula óssea. O objetivo desse trabalho é relatar o caso de um cão macho, sem raça definida, de apenas um ano de idade, atendido no Hospital Universitário de Medicina Veterinária Prof. Firmino Mársico Filho (HUVET) da Universidade Federal Fluminense (UFF) com queixa principal de inapetência e diarreia há três dias e que foi diagnosticado com essa neoplasia por meio da sintomatologia clínica, resultados do hemograma e do mielograma. O paciente apresentava valores exacerbados de linfócitos (553.094 células/µL), além de anemia, trombocitopenia, hipoalbuminemia e elevação da atividade das enzimas fosfatase alcalina e ALT. Foram observadas manchas de Gümprecht, linfócitos atípicos apresentando anisocitose, anisocariose, intensa basofilia citoplasmática e monócitos ativados. O mielograma apresentou também um aumento de linfócitos e contagem de linfoblastos superior a 30% na medula, confirmando o diagnóstico de leucemia linfoblástica aguda. Ademais, posteriormente, foi realizado exame de Reação em Cadeia de Polimerase (PCR) para rearranjos de receptores de antígenos e foi detectado clonalidade para linfócitos T. O animal foi submetido à quimioterapia (protocolo com ciclofosfamida, vincristina e prednisona), mas não resistiu à gravidade do quadro, vindo a óbito após a primeira sessão, pouco tempo após o diagnóstico.

Acute lymphoblastic leukemia (LLA) is a disease with a lymphoid origin and consists of the proliferation of neoplastic cells in the bone marrow. The aim of this study was to report the case of only one year old mixed breed male dog, attended at the University Hospital of Veterinary Medicine Prof. Firmino Mársico Filho (HUVET) from Universidade Federal Fluminense (UFF), with major complaint of inappetence and diarrhea three days ago and which was diagnosed with this neoplasm through clinical symptoms, complete blood count and myelogram results. The patient had increased values of lymphocytes (553,094 cells/μL), in addition to anemia, thrombocytopenia, hypoalbuminemia and elevated alkaline phosphatase and ALT activities. Gümprecht shadows, atypical lymphocytes presenting anisocytosis, anisocariosis, and severe cytoplasmic basophilia and activated monocytes were observed. Myelogram also showed an increase in lymphocytes and a lymphoblastic count greater than 30% in the marrow, confirming the diagnosis of LLA. In addition, polymerase chain reaction (PCR) for antigen receptor rearrangements was performed and clonality for T lymphocytes was detected. The animal underwent chemotherapy (protocol with cyclophosphamide, vincristine and prednisone), but did not withstand the severity of the disease, coming to death after the first session, shortly after diagnosis.

Microvessel density assessment in canine mammary carcinomas as a predictive factor for metronomic chemotherapy / Mensuração da densidade microvascular em carcinomas mamários caninos como fator preditivo à quimioterapia metronômica

The canine mammary tumor is the neoplasia that most commonly affects intact female dogs (not spayed) in routine veterinary practice. Canine mammary tumor therapy is a challenge because only few effective treatments have been described for high-grade tumors in veterinary medicine. One such therapeutic option that slows down tumor growth is metronomic chemotherapy (MC), a therapeutic modality that acts by decreasing tumor angiogenesis. Quantification of intratumoral microvessel density (MVD) has been proposed as a means to evaluate the effectiveness of MC in human and canine tumors. In this study, MVD is proposed as a predictive factor for the effectiveness of MC in canine mammary tumors. Twenty female dogs with mammary carcinoma were equally distributed into a mastectomy group treated only with mastectomy, and a MC group treated with MC (cyclophosphamide and piroxicam) orally and daily for 28 days followed by mastectomy. Mammary tumors were classified and graded histologically. MVD was ascertained by CD31 immunostaining. The analysis showed statistically significant difference in MVD scores between groups, corroborating a quantitative reduction in tumor microvasculature in the group treated with MC. Our findings suggest that MVD may be an important predictive factor for the selection of female dogs with malignant mammary tumors that may benefit from MC.(AU)

O tumor mamário canino é a neoplasia que mais comumente acomete cadelas não castradas na rotina veterinária. A terapia para a neoplasia mamária canina é um desafio, com poucos tratamentos eficazes descritos em medicina veterinária, especialmente para as neoplasias de alto grau. Uma opção terapêutica que diminui o crescimento tumoral é a quimioterapia metronômica (QM). A QM é uma modalidade terapêutica que age pelo decréscimo da angiogênese tumoral. Para avaliação da eficácia da QM tem sido proposta a quantificação da densidade microvascular (DMV) em neoplasias caninas. Neste estudo foi proposta a mensuração da DMV como fator preditivo à utilização da QM em neoplasias mamárias caninas. Foram utilizadas 20 (vinte) cadelas com carcinomas mamários malignos sendo um grupo mastectomia, tratado somente por mastectomia, e um grupo QM, em que foi empregada a QM (ciclofosfamida e piroxicam) ambos oralmente e de uso diário por 28 dias seguida de mastectomia. As neoplasias mamárias foram histologicamente classificadas e graduadas. A DMV foi obtida por imunomarcação utilizando o anticorpo CD31. A análise estatística mostrou diferença na DMV entre os grupos, evidenciando redução quantitativa na microvasculatura tumoral no grupo tratado com quimioterapia metronômica. Com base neste resultado é possível afirmar que a DMV pode vir a ser um fator preditivo de importância para a seleção de cadelas portadoras de neoplasia mamária maligna que possam vir a se beneficiar da quimioterapia metronômica.(AU)