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This report described the use of acoustic radiation force impulse (ARFI) elastography in the diagnosis of two cases of canine malignant peripheral nerve sheath tumors. Both patients presented with lameness in the thoracic limb and no response to previous clinical treatment or trauma history. Physical examination revealed muscular atrophy in one of the thoracic limbs, in both dogs. B-mode axillary ultrasound showed the presence of a predominantly hypoechogenic, heterogeneous, irregular, nonencapsulated nodule with adjacent reactivity, measuring approximately 20.1 mm x 15.4 mm in the first case and 18.3 mm x 10.7 mm in the second. ARFI elastography was performed, showing areas of significant stiffness, with an average shear wave velocity of 4.12 m/s (case 1) and 4.35 m/s (case 2), suggesting malignancy. In both cases, the affected limb was amputated, and the tumors sent for histopathological analysis, which were; subsequently, diagnosed as malignant tumors of the peripheral nerve sheath. The ultrasonographic methods used were essential in the diagnosis and therapeutic conduct.

O objetivo deste relato é descrever o auxílio da elastografia por impulso de força de radiação acústica (ARFI) no diagnóstico de dois casos de tumores malignos da bainha dos nervos periféricos em canídeos. Ambos os pacientes apresentavam claudicação em membro torácico e já haviam sido tratados clinicamente por outros profissionais, sem resposta ao tratamento ou histórico de trauma. Ao exame físico, foi observada atrofia muscular em apenas um dos membros torácicos, nos dois casos. Foi realizado exame ultrassonográfico axilar. Na avaliação modo B, foi observada a presença de estrutura nodular, predominantemente hipoecogênica, heterogênea, irregular, não encapsulada e com reatividade adjacente, medindo aproximadamente 20.1 mm x 15.4 mm no primeiro caso e 18.3 mm x 10.7 mm no segundo caso. Foi realizada elastografia ARFI, demonstrando a presença de áreas de maior rigidez, com velocidade de ondas de cisalhamento média de 4.12 m/s (caso 1) e 4.35 m/s (caso 2), sugerindo malignidade. Em ambos os casos, foi realizada amputação do membro afetado e os nódulos removidos foram encaminhados para análise histopatológica, na qual se obteve o diagnóstico de tumor maligno da bainha de nervo periférico. Os métodos ultrassonográficos realizados nesses casos foram essenciais para o diagnóstico e conduta terapêutica.

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Oral squamous cell carcinoma is a common malignant tumor of epithelial cells in dogs. This tumor metastasizes slowly and primarily affects the gingiva. Despite its importance, few studies document this cancer in wild canids. A young adult female hoary fox (Lycalopex vetulus) kept in captivity at Associação Mata Ciliar (Jundiaí, SP, Brazil) exhibited clinical signs such as weakness, prostration, and severe oral bleeding. After anesthetizing the animal, a reddish, friable verrucous formation was observed on the upper and lower lip, as well as on the maxillary and mandibular gingiva on the right side of the mouth, extending towards the bony palate. A biopsy of this mass was performed, followed by histopathological and immunohistochemical evaluation. Histopathology indicated an atypical squamous proliferation with inflammatory features suggestive of poorly differentiated squamous cell carcinoma, which was confirmed by immunohistochemistry through the positive expression of antibodies AE1AE3, p63, and CK14. The proliferation marker ki67 was used to assess the aggressiveness and malignancy of the tumor, and it was found in approximately 80% of the neoplastic cells. Because of the poor prognosis, the hoary fox was euthanized, and a necropsy was performed. Histopathological analysis of the tissues revealed lung metastasis, suppurative bronchopneumonia, and renal metastasis associated with neutrophilic interstitial nephritis and tubular necrosis. The present report describes this type of neoplasm for the first time in a hoary fox and one of the few observed in wild canids. The scarcity of research on neoplasm incidence in wild canids in Brazil emphasizes the need for further investigations to understand tumor development in these species better.(AU)

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Neoplasms are an important cause of morbidity and mortality in horses, with squamous cell carcinoma (SCC), also called squamous cell carcinoma, being the most common genital malignant tumor in the species and the most common neoplasm in horses in the State of São Paulo. Neoplasms frequently infiltrate the corpus cavernosum and can cause metastases in regional lymph nodes, generally having a guarded to poor prognosis due to local invasion and recurrence. Given the importance of the disease, the objective was to verify whether there is a difference in the expression pattern of immunomarkers of apoptosis and cell adhesion, according to the degree of cellular differentiation of the neoplasms. Twenty equine penile SCC samples from the Animal Pathology Service of the Veterinary Hospital of the Faculty of Veterinary Medicine and Animal Science of the University of São Paulo were histologically analyzed and classified according to their degree of differentiation. In addition, they were also subjected to the immunohistochemistry technique, with the immunomarkers Caspase-3 and E-cadherin. Data were analyzed using Kendall's correlation and the Mann-Whitney test. It was found that there is a positive correlation between the expression of immunomarkers and that there is no statistically significant difference in the expression of immunomarkers according to the degree of differentiation.

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GISTs can be benign or malignant, and they have been reported in a wide variety of species, including humans, non-human primates, dogs, and cats; however, reports of this tumor in birds are rare. These neoplasms are seen in the gastrointestinal tract and are derived from the Cajal Cells responsible for regulating gastrointestinal motility. We report a case of a gastrointestinal stromal tumor in a scarlet macaw (Ara chloropterus) that was referred to necropsy at the Veterinary Hospital of the Federal University of Paraíba (UFPB), Northeastern Brazil. Macroscopically, the proventriculus and ventriculus were dilated, and the walls of both organs were thickened by a firm, ulcerated mass covered by fibrin strands. In the histopathology, the proventriculus presented an expansive, non-encapsulated neoplasm formed by homogeneous spindle cells, with eosinophilic cytoplasm, indistinct borders, mild to moderate pleomorphism, and rare mitotic figures, being suggestive of a leiomyoma. In immunohistochemistry, a positive multifocal immunolabeling for the C-KIT proto-oncogene was observed in the cytoplasm of neoplastic spindle cells, thus compatible with a gastrointestinal stromal tumor (GIST). The occurrence of GISTs in avian species might have been overlooked, and the authors recommend that previously reported gastrointestinal leiomyomas or leiomyosarcomas be tested for this immunomarker to rule out the possibility of GISTs.(AU)

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Background: The Transmissible Venereal Tumour (TVT) is a round cell neoplasm that affects dogs. Its localisation is predominantly venereal; however, it can be found in extragenital regions, such as skin, nostrils, mouth and eyes. This paper describes a case of nasal TVT in a geriatric dog, performing its clinical, laboratory, therapeutic and prognostic analysis. Case: A 13-year-old male dog, mixed breed, non-castrated, domiciled, weighing 19,200 kg, was attended at the Small Animal Medical Clinic (CMPA) of the University Veterinary Hospital (HVU) of the Multidisciplinary Centre of the Barra Campus, Federal University of Western Bahia (UFOB), presenting cachexia, reactive lymph nodes except the popliteal ones, dehydration, dyspnoea, arrhythmia, frequent sneezing with serous and yellowish nasal discharge, cough, difficulty in breathing, increased volume in the face (left nasal plane), enlarged volume above the right eye with a suppurative wound just below. The animal's haemogram revealed the presence of normocytic normochromic anaemia, neutrophilic leukocytosis with left regenerative shift and hyperproteinaemia. The serum biochemical tests for renal function (urea and creatinine) and hepatic function (ALT, AST and AF) showed normal levels. The cytological evaluation showed a mono-morphic population of large cells with a round nucleus, condensed chromatin and 1 to 2 prominent nucleoli, abundant and slightly basophilic cytoplasm, with multiple punctuated vacuoles, showing discrete anisocytosis and anisokaryosis and mitotic figures, confirming a case of TVT. In addition, the presence of neutrophils was evidenced, indicating an inflammatory process. Simultaneously, an X-ray of the skull was requested, which was not returned. A chemotherapy protocol was instituted using vincristine sulphate [0.025 mg/kg IV], for 5 sessions with an interval of 1 week between each session, clinical and laboratory monitoring of the regression of neoplastic cells, demonstrating total efficacy. It is worth noting that after the 2nd application of the pharmaceutical, the animal presented adverse reactions, with clinical symptoms of emesis, decreased appetite and weight loss; so, the animal was then subjected to fluid therapy, treatment with immunostimulants, appetite stimulants and antiemetics, which influenced its clinical improvement. Discussion: The importance of complementary diagnostic tests in the routine of veterinary clinics and hospitals is notice-able, aimed at establishing the diagnosis and therapeutic monitoring of diseases. In the present report, diverging from the majority of cases described in the literature, the animal showed signs of neoplasia at 13 years of age, in a context of reduced sexual activity. It is believed that the fact that he has free access to the street and has olfactory habits inherent to the canine species in terms of contact with the genital region of other animals, left him exposed to factors that determined the transmissibility of the neoplasm. Weekly clinical follow-up as well as laboratory tests, was essential to ascertain the effectiveness of the treatment, the presence of adverse reactions and the introduction of new drugs. The normocytic normo-chromic anaemia possibly occurred in response to the nodular and haemorrhagic characteristics of the tumour tissue. The leukocytosis due to neutrophilia and hyperproteinaemia would be related to the occurrence of an acute infectious process, probably bacterial. It is concluded that although geriatric patients present immunosuppression more easily than other age groups, in cases of TVT, the therapeutic approach with vincristine sulphate, and the clinical and laboratory follow-up adopted influence the good prognosis concerning neoplastic regression.

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Background: A 10-year-old spayed bitch with hip dysplasia was referred for periarticular ultrasound evaluation. A poorly marginated structure of mixed echogenicity, predominantly hypoechoic, with heterogeneous echotexture, was identified in the vastus lateralis muscle of the right pelvic limb with increased stiffness, assessed using acoustic radiation force impulse (ARFI) elastography, compared to that of the adjacent muscle tissues, and intense vascularization by pulsed Doppler and contrast-enhanced ultrasound (CEUS). Guided biopsy was performed to confirm the diagnosis of hemangiosarcoma. The objective of this study was to describe B-mode ultrasound, CEUS, and ARFI findings of hemangiosarcoma in the vastus lateralis musculature of a bitch. Case: A 10-year-old spayed bitch Golden Retriever weighing 36 kg was evaluated for pelvic limb lameness. The patient presented with bilateral pain during hip extension. The primary diagnostic suspicion was degenerative joint disease and secondary hip dysplasia. The patient was referred for imaging evaluation of the hip joints (radiography and ultrasound) under anesthesia. Right lateral and ventrodorsal projections with the pelvic limbs extended were obtained to confirm the diagnosis. In the right pelvic limb, an amorphous hypoechoic structure with irregular contours and heterogeneous echotexture was observed in the vastus lateralis muscle. In ARFI elastography, it was possible to identify differences in tissue stiffness between healthy and compromised portions. Pulsed-wave Doppler evaluation demonstrated an arterial waveform pattern with a peak systolic velocity of 38.8 cm/s, end-diastolic velocity of 6.9 cm/s, pulsatility index of 1.76, and resistive index of 0.82. CEUS study identified a mean peak of 27.26 %, mean time to peak of 39.95 s, and mean transmission time of 49.96 s. The popliteal lymph node was hyperechoic and heterogeneous in B-mode. In ARFI elastography, the average stiffness was 2.52 m/s, and the CEUS obtained an average peak of 19.98%, average time to peak of 17.52 s, and mean transit time of 22.83 s. Doppler assessment revealed no clear vascularization in the lymph node. Thoracic radiography in 3 projections and abdominal ultrasonography were performed. Radiographic evidence of pulmonary nodules was not observed. On abdominal ultrasound evaluation, it was possible to identify changes in the spleen, which presented with splenomegaly, mixed echogenicity, and heterogeneous echotexture. The animal underwent ultrasound-guided muscle biopsy, which confirmed the presence of hemangiosarcoma in the muscle. The bitch was referred for splenectomy and lymphadenectomy of the right popliteal, which confirmed neoplastic involvement of the same neoplasm. Discussion: On B-mode ultrasound, the observed changes were similar to those in a report of hemangiosarcoma in the muscles of the chest wall in dogs, which contributed to the diagnosis. Although it was only one patient, ARFI elastography results suggest that muscle hemangiosarcoma tends to follow the same elastographic characteristics as malignant lesions in other tissues. Additionally, the popliteal lymph node had a stiffness suggestive of malignancy (mean 2.52 m/s) because it presented a similar result and greater elasticity of metastatic axillary lymph nodes in bitches (>2.5 m/s) and women (> 1.44 m/s) with breast tumor. With CEUS, it was possible to identify vascularization in the sentinel lymph node that was not visible by pulsed Doppler, and in muscle mass. The findings of this report provided relevant results on muscle hemangiosarcoma in a bitch and demonstrated that the information obtained with the association of imaging methods supported the malignancy criteria described in other studies.

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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.

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Background: Lymphoma is a hematopoietic tumor characterized by the clonal proliferation of malignant lymphocytes. It is the most frequently observed neoplasm in cats, accounting for approximately 33% of all tumors diagnosed in this species. Primary renal lymphoma accounts for approximately 1.5% of tumors diagnosed in felines and usually affects middle-aged to elderly cats and European breeds. This study describes a case of renal lymphoma in a feline, emphasizing the clinical, laboratory, imaging, and anatomopathological findings of this disease. Case: A 3-year-old spayed mixed breed cat, weighing 3.3 kg, presented apathy, lack of appetite, prostration, polydipsia, restlessness, tremors, sudden incoordination, and increased abdominal volume. Blood counts, serum biochemistry, urinalysis, radiography, and abdominal ultrasonography were performed. Blood count showed leukocytosis, with many atypical lymphocytes and thrombocytopenia. Serum biochemistry revealed azotemia, mild hypokalemia, and low alkaline phosphatase levels. Radiography showed an increase in the kidney dimensions and asymmetry of the kidney silhouettes, indicating a mass effect. Ultrasonography revealed enlarged dimensions, irregular contours, and bilateral nodular features. However, the corticomedullary definition was preserved. Kidney cytology revealed a high number of lymphocytes in smears, with a predominance of medium to large lymphocytes, suggestive of lymphoma. The animal underwent chemotherapy with lomustine, vincristine, prednisolone, and doxorubicin; however, due to the recurrence of clinical signs, the animal died. Macroscopically, the kidneys were enlarged, irregularly contoured, and white in color. When cut, a loss of renal architecture was noted, with blurring of the cortical and medullary regions. Histologically, the renal architecture was obliterated and replaced by a monomorphic population of atypical lymphocytes. The histological diagnosis was compatible with diffuse renal large-cell, high-grade, immunoblastic lymphoma. Immunohistochemistry showed positive immunostaining for CD20 and PAX-5 in the cell cytoplasm and negative immunostaining for CD3. Ki67 was detected in approximately 40% of neoplastic cells. The final diagnosis was primary diffuse large B-cell renal lymphoma. Discussion: The diagnosis of primary renal lymphoma was based on the occurrence of this tumor only in the kidneys of the animal. Renal lymphoma is the most common primary neoplasm affecting cat kidneys. The diagnosis of lymphoma in animals is based on cytological and/or histological examination. In addition, the final classification is performed using immunophenotyping (T and B cells), histology, and/or cytology to evaluate the cellular and nuclear characteristics, histological organization, and growth patterns of the lymphomas. The current clinical signs are related to renal failure, including neurological signs caused by uremia. There is a relationship between the occurrence of lymphoma in felines and retroviral infection; however, it was not possible to test the animal for retroviruses. The alterations observed in hematological examinations are related to the ongoing neoplastic process. The imaging findings in this case were similar to those observed in other studies on renal lymphoma. The treatment used in this study was the L-CHOP protocol, which has been associated with the treatment of different types of lymphomas in several studies on feline lymphomas. The median survival of cats with renal lymphoma is 50days. In this case, the patient survived 30days after hospital admission.

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Mast cell tumors, which are neoplasms with variable behavior, from less aggressive to highly metastatic tumors, account for 16%­21% of cutaneous neoplasms in dogs. The diagnosis and grading of mast cell tumors are based on cytological analysis and histological evaluation, which facilitate appropriate planning for surgical and chemotherapeutic treatment. Surgical resection with safety margins of 2­3 cm is considered the best therapeutic option; however, postoperative complications, such as delayed healing, necrosis, suture dehiscence, and occurrence of seroma, are reported. It is essential to understand the biology of mast cell tumors because prognostic factors directly influence the efficacy of the treatment and the quality of life of the patient. Here, we conducted a retrospective study of dogs submitted to surgical resection of cutaneous mast cell tumors, and analyzed the prognostic factors and occurrence of postoperative complications. The results showed that low grade mast cell tumors were associated with a lower occurrence of ulceration, metastasis, recurrence, lack of need for adjuvant therapy, and occurrence of paraneoplastic syndrome compared to those of a higher grade. We also compared the association between demanding or compromised margins with the presence of postoperative complications. The results showed that high grade mast cell tumors have a greater metastatic potential and that the presence of neoplastic cells in the adjacent tissues leads to a greater malignancy and postoperative complications

Mastocitomas representam de 16 a 21% das neoplasias cutâneas em cães. São neoplasmas com comportamentos variáveis, de tumores pouco agressivos até altamente metastáticos. Seu diagnóstico é baseado na análise citológica e avaliação histológica para determinação da graduação, sendo possível realizar o adequado planejamento do tratamento cirúrgico e qui-mioterápico. A ressecção cirúrgica com margens de segurança de 2 a 3 cm é considerada a melhor opção terapêutica, entretanto, são relatadas complicações no pós-operatório como retardado na cicatrização, necrose, deiscência de sutura e ocorrência de seroma. É indispensável o entendimento da biologia do tumor, pois fatores prognósticos implicam diretamente na eficácia do tratamento e na qualidade de vida do paciente. O presente trabalho objetivou a realização de estudo retrospectivo de cães submetidos à ressecção cirúrgica de mastocitoma cutâneo, com análise dos fatores prognósticos e da ocorrência de complicações pós-operatórias. Foi possível observar que os mastocitomas de baixo grau apresentam menor ocorrência de ulceração, metástase, recidiva, ausência de necessidade de terapia adjuvante e ocorrência síndrome paraneoplásica comparativamente aos de maior grau. Foi possível ainda, a comparação da associação entre margens exíguas ou comprometidas com a presença de complicações pós-operatórias. Os resultados demonstraram que mastocitomas de alto grau tem maior potencial metastático e a presença de células neoplásicas nos tecidos adjacentes acarretam em comportamento de maior malignidade e complicações pós-operatórias

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Hemangiosarcoma (HSA) is a malignant tumor derived from the endothelium of vessels, and primary renal HSA is a rare variant of the disease. This study aimed to report a case of unilateral primary renal HSA with pulmonary and brain metastasis in a dog. A 10-year-old mixed-breed male dog was treated at the Hospital Professor Ricardo Alexandre Hippler from Universidade Vila Velha (HV-UVV) with signs of hematuria. A mass in the left kidney was detected by ultrasound, and no metastasis was detected on chest radiography. Unilateral nephrectomy was performed, and the material underwent histopathological examination, which was concluded as HSA. The animal died 48 days after surgery, and a necropsy was performed, showing marked hemothorax and multifocal metastasis of HSA in the lung and brain. The absence of nodules at other sites before surgery indicates a primary renal origin. The late diagnosis of the disease may have contributed to the spread of metastasis and, consequently, the development of hemothorax. Histopathological and necroscopic examinations were essential to confirm the diagnosis.(AU)

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Background: Hepatic tumors of primary origin account for 0.6% to 2.9% of cases in canine species, less common than hepatic metastases. The hepatic tumors are divided into hepatocellular tumors, neuroendocrine tumors, bile duct tumors or cholangiocarcinomas, and mesenchymal tumors. Cholangiocarcinomas, are classified according to their origin, being intrahepatic, extrahepatic, or gallbladder type. Cholangiocarcinomas are considered rare in dogs and cats with a ratio of 29% to 71% compared to hepatocellular carcinomas, accounting for 9% of the hepatic tumors. The present study aims to describe a case of cholangiocarcinoma in a bitch, focusing on the diagnostic approach. Case: A 10-year-old castrated bitch Poodle was attended presenting hypoglycemia and seizure crisis. The patient had previous exams of hemogram and serum biochemical profile, showing a discrete increase of the hepatic enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), besides hypoglycemia. Previous ultrasound exam revealed the presence of a hepatic mass located between the right and square lobes, immeasurable, and significant splenomegaly. Abdominal palpation revealed the presence of immeasurable abdominal formation of undetermined origin. Abdominal computerized tomography (CT), glycemic curve, and insulin dosage were requested. Tomography exam showed an increase in hepatic volume with the presence of a heterogeneous formation in the right lateral lobe topography; increase in spleen dimensions and the presence of multiple nodules; and the presence of a nodule in the right lung, at the caudal thoracic region. The glycemic curve showed acute variations, and insulin dosage was between normal values. The animal was referred for surgery, as in abdominocentesis, it was observed the presence of hemorrhagic fluid, confirming active bleeding by ultrasonography. The owners chose for euthanasia. In the post-mortem evaluation the main lesion was confirmed of hepatic origin, with a massive, irregular, cavitary presentation, involving multiple hepatic lobes, and a single nodule was observed in the right caudal lobe of the right lung. Histopathological evaluation was considered inconclusive. Immunohistochemistry was performed and the association of the immunohistochemical profile with the morphological characteristics indicated diagnosis of cholangiocarcinoma. Discussion: The related symptomatology, in hepatic neoplasms, is generally considered non-specific, with reports of lethargy, vomiting, dyspnea, anorexia and weight loss, however, the dog in this study presented a unique manifestation of hypoglycemia and one episode of convulsive crisis resulting from it. The clinical manifestation observed was extremely unspecific making initial diagnosis difficult. The ultrasonographic examination was effective in evidencing the abdominal mass. In addition, abdominal CT was also performed, which confirmed the hepatic origin, detailing the macroscopic aspect. Biochemical analyses of ALT and AST showed a discrete increase. Biochemical changes may occur in dogs with hepatic neoplasms, although they are not specific. Functional pancreatic beta-cell tumors producing insulin are the most common cause of paraneoplastic hypoglycemia, although in the case the insulin dosage was within normal limits. In cases of nonislet cell tumor the mechanism is frequently associated with the production of insulin-like growth factor (IGF). In most cases the definitive diagnosis of cholangiocarcinoma can be obtained by histopathological examination, although in the present report the result obtained was inconclusive, requiring an immunohistochemical examination. Due to the aggressive and metastatic character of this neoplastic type, early detection becomes extremely important in order to maximize therapeutic chances, however, diagnosis may be difficult.

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The article describes the case of a 3 year 6 months old Guinea Pig (Cavia porcellus) that was assisted at the Wildlife and Exotic Animal Practice of the Faculty of Veterinary Sciences, National University of Asunción. The patient presented a hard mass in the right hind limb extending from the proximal portion of the femur, projecting caudally to the proximal tuberosity of the calcaneus, with an increase in temperature, and a marked increase in sensitivity. Radiographic diagnosis refers to a mass with amorphous areas of mineral density. Fine needle aspiration puncture revealed an undifferentiated malignant proliferative process, requiring histopathological analysis to characterize the process. Disarticulation was performed and subsequent histopathologic diagnosis under hematoxylin-eosin and Masson's trichrome stain revealed fibroblastic osteosarcoma.(AU)

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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.

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Background: Osteosarcoma is the most observed primary bone tumor in dogs, and may affect the appendicular and axial skeletons. In addition, it may be present in extraskeletal form, accounting for only 1% of cases. As shown by few reports in the literature, the involvement of the intestinal region by is rare. The objective of this study was to report the case of a 13-year-old Yorkshire dog, submitted to an exploratory laparotomy for suspected partial intestinal obstruction, diagnosed with extraskeletal osteosarcoma. Case: A 13-year-old dog, Yorkshire Terrier, male, presented clinical signs of gastrointestinal abnormalities. An ultrasound examination was performed and was found a mass in small intestine region with wall and lumen invasion. Then, was realized exploratory laparotomy and detected intestinal obstruction due to a mass with approximately 5.0 x 6.0 x 4.4 cm localized in duodenum. Surgical removal was performed and the sample sent to the veterinary diagnostic laboratory for histopathological examination. The sample had an irregular surface and firm consistency. In addition, when cut, the mass enveloped the intestinal layers and sometimes obstructed the lumen. Then, the sample were processed routinely for histopathology. After that, in microscopy evaluation was detected cell proliferation, affecting all layers of intestine. In detail, cells were elongated with pleomorphism marked and atypical mitosis. In addition, there was production of cartilage and bone matrix. So, due the absence of others sites, the neoplasm was considered primary of intestine. After that, to evaluate the expression of KI-67 and COX-2 was performed, and the cell proliferation index was 54.0% and the COX-2 expression was moderate in less than 10% of neoplastic cells. After the surgery, the patient was hospitalized for a week and continue the treatment in home. Afterwards, the tutor received the diagnosis, but even though he was instructed on the severity of the case, he chose not to undergo chemotherapy. After three months, the patient presented abdominal fluid and nodules in your liver, suggesting metastasis, but without diagnosis confirmation. The patient died five months after the diagnosis of extraskeletal osteosarcoma. However, no necropsy was realized, impossibility the diagnosis confirm. Discussion: The frequency of extraskeletal osteosarcoma in dogs remains unknown, with the mammary glands being the most affected site. In the present study, osteosarcoma affects the duodenal region and no reports of this neoplasm in the duodenum of dogs have been found in the literature. The clinical sign of dyschezia was important for the tutor to refer the animal to the veterinarian and perform the ultrasound in an attempt to elucidate the case, as the tumor mass is not always palpable. Histopathological examination and immunohistochemistry were necessary for the differential diagnosis and to establish the prognosis, although after the surgery the tutor chose not to perform chemotherapy. Extraskeletal osteosarcoma are usually highly metastatic, mainly affecting the lymph nodes and liver. In this case, the patient presented a liver nodule three months after the tumor removal surgery, but unfortunately, there was no diagnostic confirmation. Such neoplastic type is rarer and more aggressive than appendicular and axial osteosarcoma, with an average survival of 1 to 3 months. In this case, as a necropsy was not obtained, we cannot attribute the survival time to the disease. The survival rates of osteosarcomas in dogs are few months, but in the present case, although the patient died five months after surgery, the failure to perform a necropsy compromises the attribution of survival time to extraskeletal osteosarcoma.

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Os mielolipomas são neoplasias benignas de células adiposas que contêm elementos hematopoiéticos, consideradas infrequentes e de difícil diagnóstico. O seguinte trabalho relata um caso de mielolipoma esplênico diagnosticado em um felino na região Sul do Rio Grande do Sul. A paciente foi encaminhada para atendimento em uma clínica veterinária, porém ocorreu o óbito. Na necropsia foi observado um nódulo no baço, medindo 2,0cm de diâmetro, com superfície de corte de coloração mais clara que o órgão e de consistência macia. Histologicamente havia proliferação de tecido adiposo maduro e bem diferenciado, com células de formatos redondos a ovais, com núcleos pequenos e periféricos junto à grande quantidade de células hematopoiéticas constituídas por megacariócitos, eritrócitos maduros, além de macrófagos, linfócitos e plasmócitos. Estes componentes celulares foram visualizados, também, em outros órgãos, sendo eles: o pâncreas, rins, fígado e coração, caracterizando a neoplasia. Há poucas descrições de mielolipoma esplênico em felinos na literatura. No Brasil há descrição desta neoplasia no baço somente em caninos. Apesar de se tratar de uma neoplasia de caráter benigno, ela deve ser considerada no diagnóstico diferencial de patologias que acometem o sistema linfóide.

Myelolipomas are benign neoplasms of adipose cells that contain hematopoietic elements, considered infrequent and difficult to diagnose. The following paper reports a case of splenic myelolipoma diagnosed in a feline in the southern region of Rio Grande do Sul. The patient was referred for care at a veterinary clinic but died. Macroscopically, a nodule measuring 2.0 cm in diameter was observed in the spleen, with a cut surface that was lighter in color than the organ and soft in consistency. Histologically, there was proliferation of mature and well-differentiated adipose tissue, with cells of round to oval shapes, with small and peripheral nuclei, together with a large number of hematopoietic cells consisting of megakaryocytes, mature erythrocytes, in addition to macrophages, lymphocytes and plasma cells. These cellular components were also visualized in other organs, namely the pancreas, kidneys, liver and heart, characterizing the neoplasm. There are few descriptions of splenic myelolipoma in felines in the literature. In Brazil there is a description of this neoplasm in the spleen only in canines. Despite being a benign neoplasm, it should be considered in the differential diagnosis of pathologies that affect the lymphoid system.

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Background: The uncontrolled multiplication of Sertoli cells causes Sertoli cell tumor or Sertolioma. Because of this, the level of estrogen in the bloodstream increases rapidly and approximately 25% of dogs with this tumor develop feminization syndrome. Testicular neoplasms are more common in dogs than cats, and are often found in elderly patients. This work aims to describe the clinical signs of the feminization syndrome and the treatment instituted in a canine diagnosed with sertolioma. Case: A 18-year-old male canine, 19.5 kg of body mass, with an increase in testicular volume for about 2 years, was treated at the University Veterinary Hospital. On clinical examination, a matte and brittle coat, alopecia on the hind limbs and gynecomastia were observed. Also noted, non-harmonious aspect of the scrotum, pendular foreskin, atrophied right testicle and hyperplastic left, scrotal hyperthermia and absence of pain. In addition, as a result of the hyperestrogenism resulting from the neoplasm, the paraneoplastic syndrome of feminization, the patient also presented galactorrhea, pendular foreskin, atrophy of the penis and the contralateral testicle, dermatopathies, such as bilateral symmetrical alopecia of the flanks, easily removable hair and variable hyperpigmentation. Rectal body temperature of 38.6°C, clear lung auscultation and muffled cardiac auscultation. The results of laboratory tests showed changes such as thrombocytopenia, platelet counts below the reference levels, platelet count of 163,000/uL. There were no alterations that represented metastases in the imaging exams, such as in the chest X-ray in three incidences and in the abdominal ultrasonography. Then, we opted for the surgical procedure of orchiectomy, with the traditional technique of three clamps, associated with total ablation of the scrotum. Samples were sent to the histopathology laboratory and the diagnosis of sertolioma was confirmed. At 10, 30 and 90 days after the operation, the patient was reassessed for possible recurrences or alterations, but there were no complications or recurrence after the procedure. Discussion: Neoplasms of the male reproductive system are common in dogs. Sertolioma is considered one of the most frequent neoplasms in elderly dogs and that results in systemic clinical signs. This is in line with the 18-year-old dog described in the present report. In addition, it may result in clinical signs resulting from hyperestrogenism resulting from the neoplasm that is called paraneoplastic feminization syndrome. The characteristics of this syndrome are: gynecomastia, galactorrhea, pendular foreskin, atrophy of the penis and contralateral testicle, associated with dermatopathies, such as symmetrical bilateral alopecia. All these clinical signs were present. The diagnosis is made through complete anamnesis, complete clinical examination and complementary examination such as ultrasound help in the presumptive diagnosis, but only with histopathology can it be confirmed. In the clinical approach, histopathology was performed to close the diagnosis. Treatment is behind orchiectomy and total ablation of the scrotum, which was performed in the reported case. The treatment of choice was easy to apply, in addition to improving the patient's quality of life, promoting rapid post-surgical healing and an early return to normal life. However, for the effectiveness of the technique, the early diagnosis and collaboration of tutors is fundamental.

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Background: Primary lung neoplasms are uncommon in veterinary medicine, and when they develop, they are more frequently observed to be of epithelial origin. Although chondrosarcomas are the second most diagnosed type of neoplasm in dogs at skeletal sites, their development in extraskeletal tissues, including the spleen, aorta, heart, tongue, peritoneum, and lungs, corresponds to approximately only 1% of cases. Therefore, the occurrence of primary pulmonary chondrosarcoma is considered very rare in domestic animals. Considering the rare occurrence and scarcity of data regarding its development, the present report describes the clinical and pathological aspects of a case of primary pulmonary chondrosarcoma in a bitch. Case: A 8-year-old mixed-breed bitch, weighing 14.2 kg, was examined at one private veterinary clinic with the principal complaint of prolonged respiratory distress and resistance to exercise. Clinical evaluation revealed tachypnea with expiratory dyspnea due to intense pleural effusion, tachycardia, and diffusely pale mucous membranes. Thoracocentesis was performed with drainage of 1000 mL of modified transudate, and fluid cytology, blood count, and chest radiography were performed. Cytological analysis of the thoracic fluid did not identify neoplastic cells, the blood count showed intense regenerative anemia, and the radiograph showed an extensive area of consolidation in the left caudal lung lobe, compatible with neoplasia. The results of the tests performed, in addition to the evolution of the clinical picture and the impossibility of performing the indicated surgical intervention, culminated in the patient's unfavorable prognosis, followed by euthanasia, necropsy, and histopathological evaluation of the collected material. Necropsy revealed a white neoplastic formation with reddish areas and firm consistency that diffused into the parenchyma of the left caudal lung lobe with invasion of the rib cage, fracture of the fifth and sixth left ribs, diaphragmatic metastasis, intense hydrothorax, and moderate hydroperitoneum. Microscopically, in the histological sections of the lung and diaphragm, poorly differentiated mesenchymal cells with moderate anisocytosis and anisokaryosis and interspersed with them, moderately differentiated chondrocytes surrounded by chondroid matrix, moderate anisocytosis and anisokaryosis, and a low mitotic index culminated in the diagnosis of primary pulmonary mesenchymal chondrosarcoma. Discussion: Malignant epithelial neoplasms were suspected; however, the histopathological features observed were compatible with primary pulmonary chondrosarcoma. The characteristics of the fluid collected through thoracentesis led to its classification as a modified transudate, which is often associated with neoplastic and hemorrhagic processes; both alterations were present in this case. The diagnosis of primary pulmonary chondrosarcoma was established based on the histopathological findings since the cell type and distribution observed in the present case were compatible with the typical pattern observed in extraskeletal chondrosarcomas. An unfavorable prognosis is common in cases of primary or metastatic lung neoplasm since, in most cases, the condition is identified in the advanced stages of the disease, making therapeutic management challenging. Given the increase in the number of dog deaths due to neoplasms in recent years, this case report may contribute to a better understanding of the biological behavior of pulmonary chondrosarcoma and assist in the choice of treatment to be adopted when required.

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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)

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Plasmocytomas are neoplasms originating from plasma cells and can be subdivided into cutaneous extramedullary, non-cutaneous and multiple myeloma. The involvement of vertebrae can generate clinical signs of pain and neurological alterations according to the affected segment. The present study aims to report a case of extramedullary plasmacytoma in the thoracic spine and with consequent spinal cord compression in addition to metastasis sites, characterizing its clinicopathological aspects. The canine patient was hospitalized, submitted to laboratory and imaging tests, and medicated due to incoordination and loss of perception of limb positioning, but his clinical picture worsened, progressing to loss of movement and fecal and urinary incontinence, resulting in death. The main necropsy findings were the presence of a tumor mass along the external surface of the body of the fifth thoracic vertebra, in addition to light brown foci in the thoracic spinal cord and in the pulmonary and splenic parenchyma. Histologically, the tumor mass and light brown foci consisted of malignant cell proliferation, of plasmacytic origin, densely cellular and largely infiltrative. Thus, through the clinical picture presented, imaging tests and anatomopathological analysis, it was shown that it was a case of extramedullary plasmocytoma originating in the thoracic spine, with sites of metastasis in the spinal cord, lung and spleen.

Plasmocitomas são neoplasmas originados de plasmócitos e podem ser subdivididos em extramedular cutâneo, não cutâneo e mieloma múltiplo. O envolvimento de vértebras pode gerar sinais clínicos de dor e alterações neurológicas de acordo com o segmento afetado. O presente estudo tem como objetivo relatar um caso de plasmocitoma extramedular em coluna vertebral torácica e com consequente compressão medular além de sítios de metástases, caracterizando seus aspectos clínico-patológicos. O paciente canino foi hospitalizado, submetido a exames laboratoriais e de imagem, e medicado devido a incoordenação e perda da percepção do posicionamento dos membros, mas apresentou piora do quadro clínico evoluindo para perda dos movimentos e incontinência fecal e urinária, ocorrendo o óbito. Os principais achados de necropsia foram a presença de massa tumoral junto à superfície externa do corpo da quinta vértebra torácica, além de focos pardo-claros na medula espinhal torácica e no parênquima pulmonar e esplênico. Histologicamente, a massa tumoral e os focos pardo-claros consistiam em proliferação celular maligna, de origem plasmocitária, densamente celular e amplamente infiltrativa. Assim, através do quadro clínico apresentado, exames de imagem e da análise anatomopatológica evidenciou tratar-se de um caso de plasmocitoma extramedular originado em coluna vertebral torácica, com sítios de metástase em medula espinhal, pulmão e baço.

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Background: Malignant pleural mesothelioma (MPM) is a neoplasm with low incidence in small animals, and the possible causes are poorly elucidated but may be related to contact with asbestos. In the thoracic cavity, MMP can be localized or generalized to all cavity structures, and its clinical signs depend on this localization. Although some alternative therapies are being discussed, few studies are conclusive, with surgical intervention as the leading therapeutic option. Given this context, this report aimed to describe a case of MMP located in the mediastinum of a bitch treated with radical excision through mediated sternotomy. Case: A 7-year-old bitch of the Shar-pei breed was referred for care due to progressive weight loss and intense dyspnea. During the physical examination, dyspnea and muffled lung sounds were noted. The patient underwent hemodialysis, which showed neutrophilic leukocytosis. An abdominal ultrasound was also performed and revealed mild abdominal effusion, and chest radiography revealed an extensive tumor covering the entire chest cavity. Thoracocentesis was performed, and the material analyzed was a malignant exudate; the patient was referred to median sternotomy for exploratory purposes, and afterward, total macroscopic extirpation of the tumor was performed. A sample was sent for histopathology, and malignant mesothelioma was confirmed. The patient was discharged after 8 days of hospitalization with home treatment and did not return to the hospital. Upon contacting the guardian, we were informed that the animal had died 154 days after the procedure due to unknown causes. Discussion: Malignant pleural mesothelioma affects humans and animals; it is associated with the risk factor of contact with asbestos and the use of flea antiparasitic drugs. In small animals, its incidence is rare, albeit mesotheliomas have been reported in wild and large animals. The clinical signs are related to the location of the neoplasm. When it is located in the thoracic region, dyspnea, muffled lung sounds, cyanosis, and pleural effusion are observed in most cases. Diagnosis is usually late and incidental, although some tests, such as ultrasonography, magnetic resonance imaging, tomography, radiography, and needle biopsy, can help in the diagnosis. Histopathology is the exam of choice for definitive diagnosis, as it helps one observe the proliferation of neoplastic mesothelial cells, atypical mitosis figures, and marked cellular pleomorphism. Many therapeutic options have been discussed, including chemotherapy, immunotherapy, and anti-tumor immunization, although there is little scientific proof of their efficacy in animals. The current treatment of choice is tumor excision by surgical procedure with a palliative objective since the prognosis of the disease is unfavorable. Minimally invasive video surgery has been gaining more and more space in veterinary medicine and has proven successful in numerous cases of thoracic masses. In the present report, we chose to perform median sternotomy for total excision due to the extension of the mass that occupied the thoracic cavity practically in its entirety. Further research should be conducted to help in palliative treatments and increase the survival of patients with mesotheliomas, given that most studies are done in humans and not animals. We conclude that median sternotomy is still the therapeutic option of choice for the palliative treatment of patients with extensive thoracic pleural mesotheliomas.