Pheochromocytoma in dogs and cats

Pheochromocytoma is a functional neoplasm that produces catecholamines, located in the medullary region of the adrenal glands. As it presents nonspeciÀ c signs, scarcity of diagnostic tools and is still associated with concomitant diseases, it may not be easily considered as a differential condition among veterinarians. This is an uncommon neoplasm that usually affects dogs, with medium to advanced age and without racial predilection, being very rare in cats. Clinical manifestations vary according to the effects of catecholamines and/or circulatory impairment due to the local invasion of the tumor into adjacent structures. In this way, systemic arterial hypertension and consequences in target organs such as the central nervous system and kidneys can be observed, in addition to ocular changes. The deÀ nitive diagnosis is given by the histopathological analysis of the excised adrenal gland. However, the increase in the serum concentration of catecholamine metabolites may contribute to the conÀ rmation of the disease. Adrenalectomy is the therapy of choice, but if this is not feasible, α and ß adrenergic blocking drugs should be used. The prognosis varies from reserved to favorable, based on surgical success and the presence of metastases.(AU)

Chemodectoma in a bitch

Background: Chemodectomas, better known as tumors of the base of the heart, arise from aortic bodies, respiratory chemoreceptors located near or inside the aortic arch or originate from receptors located in the carotid arteries. Relatively rare, they affect dogs and, to a lesser extent, cats. They gain great importance when they influence the function of the cardiovascular system, with animals showing clinical signs related to congestive heart failure. Clinical diagnosis is based on symptomatology and complementary tests such as radiography, electrocardiography and echocardiography, while the definitive diagnosis is obtained by cytological and histopathological exams. This study aims to reports a case of malignant chemodectoma in a bitch, whose main symptomatology was neurological and not cardiovascular. Case: A 1-year-old Rottweiler bitch was attended with neurological alterations compatible with vestibular syndrome, hyporexia, dysphagia, apathy, melena, emesis, and purulent nasal discharge on the right nostril. On physical examination, the animal showed depressed level of consciousness, poor body condition, bilateral quemosis, paralysis of the right eye, inspiratory dyspnea and muffling of cardiac auscultation, besides a subcutaneous nodule between the scapulae. On neurological evaluation, horizontal nystagmus, head tilt to the right side, ventromedial strabismus and facial nerve paralysis on the right side were observed so that the localization of the lesion was set in peripheral vestibular system. During anesthesia for esophageal tube placement, a mass from the hard palate to the oropharynx was noted, making endotracheal intubation impossible to perform. Biopsy of this nodule was performed, and tracheostomy was indicated, but the owner opted for euthanasia before the procedure. Necropsy revealed white soft masses in the bilateral retromandibular region, on the subcutaneous tissue near the scapulae, in the right ear and since nasopharynx to the soft palate, in addition to sparse white nodules in the heart, lung, carotid artery, kidneys, right ovary, mesentery near to the spleen, and axillary lymph node. Histologically, the nodules were characterized by neoplastic cells population organized in short bundles or cords, arranged around small blood vessels surrounded by delicate connective tissue. Neoplastic cells infiltrated muscles and blood and lymphatic vessels were filled by multiple neoplastic emboli. The histological pattern of the cells allowed the diagnosis of chemodectoma. Discussion: The bitch from this case had 1-year-old when diagnosed with chemodectoma, differently from most cases from literature, that are between 7 to 15 years old. Furthermore, primarily cardiac tumors are considered rare, being chemodectoma the most common, often reported in Boxer and Boston Terrier dogs, but unusual in Rottweilers. Despites some articles mentioning seizure and Horner's Syndrome secondary to a carotid body chemodectoma, neurological signs are not commonly observed in these cases. The presence of the tumor in the middle ear region of the right side supports the occurrence of peripheral vestibular syndrome and facial nerve paralysis on the same side. Because it is a neoplasm that is usually detected late during the course of the disorder, most patients either cannot obtain diagnosis in vivo, as in this reported animal, which was in such a critical condition that underwent euthanasia, or there are no more possible therapeutic choices. In the patient described, there were numerous metastatic masses and nodules spread throughout the body. Although the typical clinical signs in animals with chemodectomas are often related to heart disease, neurological signs may also be present. This report emphasizes the importance of chemodectoma being included as a differential diagnosis in young dogs and even in breeds such as Rottweiler.

Ultrasonographic findings of abdominal thrombosis in dogs / Vascular ultrasonographic findings of abdominal thrombosis in dogs

This retrospective case series study describes the clinical and vascular ultrasound findings of 26 dogs diagnosed with abdominal thrombosis. Images were selected based on the detection of intravascular echogenic thrombus or the absence of vascular flow on color Doppler, confirmed by surgery or necropsy. Images were acquired using the Mylab 40 model, with linear and microconvex multifrequency probes. All the reports were evaluated along with the corresponding images by a veterinary diagnostic imaging radiologist. The ultrasonographic aspects evaluated were echogenicity (92.3%), anechogenicity (7.7%), vascularization (11.5%), mineralization (15.4%), and recanalization (7.7%) of the thrombosis. The vascular and hemodynamic findings were dilation of the affected vein (57.7%), total occlusion of blood flow (30.8%), presence of turbulent flow (65.38%), and visualization of smoke signal (blood flow detected as moving echogenic points in dynamic bidimensional mode) (11.5%). Neoplasms (19 cases) and nephropathies (13 cases) were the most common clinical conditions in the affected dogs. Eleven cases of vascular invasion due to adrenal neoplasms were identified. The results indicate that the vascular ultrasound examination is an important method for diagnosis, as 23 of the 26 cases did not show any clinical signs of thrombosis.

Este estudo de série de casos retrospectivos descreve os achados clínicos e ultrassonográficos vasculares de 26 cães diagnosticados com trombose. As imagens foram selecionadas baseadas na detecção de trombo ecogênico intravascular ou na ausência de fluxo vascular ao Doppler colorido, confirmado por cirurgia ou necropsia. O equipamento utilizado na aquisição das imagens foi o modelo Mylab 40, com probes multifrequenciais linear e microconvexa. Todos os relatórios foram avaliados com as imagens correspondentes por um veterinário radiologista. As características ultrassonográficas avaliadas foram: ecogenicidade (92,3%), anecogenicidade (7,7%), vascularização (11,5%), mineralização (15,4%) e recanalização (7,7%) das tromboses. Os achados vasculares e hemodinâmicos observados foram: dilatação da veia afetada (57,7%), oclusão total do fluxo sanguíneo (30,8%), presença de fluxo turbulento (65,38%) e visibilização do sinal de fumaça (fluxo vascular visível como pontos ecogênicos em modo bidimensional dinâmico) (11,5%). As neoplasias (19 casos) e as nefropatias (13 casos) foram as condições clínicas mais comuns nos cães afetados. Foram identificados 11 casos de invasão vascular decorrentes de neoplasia de adrenais. Os resultados indicaram que o exame ultrassonográfico vascular é um método importante para diagnóstico, considerando-se que, em 23 casos, não ocorreram sinais clínicos determinantes de trombose.

Metastatic vulvar squamous cell carcinoma in a mare

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

Splenic myelolipoma in a dog / Mielolipoma esplênico em um cão

Myelolipoma is a benign neoplasm composed of mature adipocytes and hematopoietic elements. This tumor is rare in dogs and cats and can develop in several organs and tissues. This report describes a case of splenic myelolipoma in a dog characterizing its clinical-pathological and ultrasonography aspects. A 9-year-old, female, mixed-breed, castrated dog was referred to the veterinary hospital with increased abdominal circumference. Ultrasonography revealed splenomegaly with masses of not measurable dimensions along the entire length of the parenchyma. The spleen was removed, and a fragment was sent for histopathological analysis. Macroscopically, the spleen was enlarged, with irregularly nodular growths that project above the surface of the organ. Nodules were red with small yellow areas. Microscopically, the spleen was effaced by a well-demarcated and not encapsulated mass composed of histologically well-differentiated neoplastic adipose tissue with islands and nests of varying proportions of hematopoietic elements. Histological examination confirmed the diagnosis of myelolipoma. Myelolipomas are observed on ultrasound images as hyperechoic masses or nodules with homogeneous echo texture. Here, ultrasound appearance involved mixed echogenicity and heterogeneous echotexture, due to the mixture of fat and non-fatty material components of the tumor.(AU)

Mielolipoma é uma neoplasia composta por adipócitos maduros e elementos hematopoiéticos. Este tumor é raro em cães e gatos e pode se desenvolver em diversos órgãos e tecidos. Descreve-se um caso de mielolipoma esplênico em um cão caracterizando seu aspecto clínico-patológico e ultrassonográfico. Um canino, fêmea, castrada, SRD, de 9 anos de idade foi encaminhada para o Hospital Veterinário com um aumento na circunferência abdominal. A ultrassonografia abdominal revelou esplenomegalia com massas de dimensões imensuráveis em toda a extensão do parênquima. Foi realizada esplenectomia total e um fragmento do baço foi encaminhado para análise histopatológica. Macroscopicamente o baço estava aumentado de tamanho, com crescimentos nodulares irregulares que se projetam acima da superfície do órgão. Os nódulos eram vermelhos com pequenas áreas amarelas. Microscopicamente foi observada uma massa bem demarcada e encapsulada composta por tecido adiposo neoplásico bem diferenciado, com ilhas e ninhos de elementos hematopoiéticos de proporção variada. O diagnóstico foi confirmado pelo exame histopatológico. Mielolipomas são observados nas imagens ultrassonográficas como massas hiperecóicas ou nódulos com ecotextura homogênea. Neste caso, o achado ultrassonográfico mostrou ecogenicidade mista e ecotextura heterogênea, provavelmente devido à mistura dos componentes do tumor com material gorduroso e não gorduroso.(AU)

Quimiodectoma em cão / Chemodectoma in a dog

Background: The chemodectoma is a rare neoplasm that originates from chemoreceptors located mainly in the aortic body,and carotid body and sinus, and responsible for detecting variations in blood pH, oxygen pressure and carbon dioxide. Dogsof brachiocephalic breeds and aged between 7 and 15 years have greater propensity. A neoplasm involves infiltrative growthin the vessels at the heart base, which leads to Congestive Heart Failure (CHF). The definitive diagnosis is performed byhistopathological and/or immunohistochemical examination. The aim was to report a case of chemiodectoma in a dog,showing the disease’s clinical characteristics.Case: A 13-year-old male undefined breed dog was examinated in the medical clinic of small animal of Veterinary Hospital,Federal Rural University of Pernambuco (UFRPE) with respiratory effort, hyporexia, and edema in face, cervical, ventralthorax and thoracic limbs, with thirty days evoluted. About physical examination, we observed cachexia, orthopneic position, cyanosis and edema with a positive Godet sign, as well as 8% dehydration degree. Thoracic auscultation presentedmixed dyspnea and muffled heart sounds. Chest radiography detected an radiopacity increase in pulmonary section andmetastatic neoplastic process associated with pleural and pericardial effusion. Fluid therapy with lactated ringer and posteriorthoracentesis in the right hemithorax region was performed for greater respiratory comfort for the patient. Hematologicalcount and biochemical profiles stated normochromic normocytic anemia, relative and absolute lymphopenia, thrombocytopenia, as well as increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The patient diedafter 12 hours when was submitted to necroscopic examination and histopathological evaluation. An infiltrative tumor ofcardiac base was observed invading the light of the right atrium, obstructing the venous return, as well as a large thrombus...

Quimiodectoma em cão / Chemodectoma in a dog

Background: The chemodectoma is a rare neoplasm that originates from chemoreceptors located mainly in the aortic body,and carotid body and sinus, and responsible for detecting variations in blood pH, oxygen pressure and carbon dioxide. Dogsof brachiocephalic breeds and aged between 7 and 15 years have greater propensity. A neoplasm involves infiltrative growthin the vessels at the heart base, which leads to Congestive Heart Failure (CHF). The definitive diagnosis is performed byhistopathological and/or immunohistochemical examination. The aim was to report a case of chemiodectoma in a dog,showing the diseases clinical characteristics.Case: A 13-year-old male undefined breed dog was examinated in the medical clinic of small animal of Veterinary Hospital,Federal Rural University of Pernambuco (UFRPE) with respiratory effort, hyporexia, and edema in face, cervical, ventralthorax and thoracic limbs, with thirty days evoluted. About physical examination, we observed cachexia, orthopneic position, cyanosis and edema with a positive Godet sign, as well as 8% dehydration degree. Thoracic auscultation presentedmixed dyspnea and muffled heart sounds. Chest radiography detected an radiopacity increase in pulmonary section andmetastatic neoplastic process associated with pleural and pericardial effusion. Fluid therapy with lactated ringer and posteriorthoracentesis in the right hemithorax region was performed for greater respiratory comfort for the patient. Hematologicalcount and biochemical profiles stated normochromic normocytic anemia, relative and absolute lymphopenia, thrombocytopenia, as well as increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The patient diedafter 12 hours when was submitted to necroscopic examination and histopathological evaluation. An infiltrative tumor ofcardiac base was observed invading the light of the right atrium, obstructing the venous return, as well as a large thrombus...(AU)

Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report / Mastocitoma cutâneo em um cachorro-do-mato vinagre (Speothos venaticus) de cativeiro: aspectos patológicos e imunofenotípicos - relato de caso

A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.(AU)

Um cachorro-vinagre (Speothos venaticus) apresentou um nódulo cutâneo pequeno na região perianal. Histologicamente havia neoplasia cutânea de células redondas e ulcerada, constituída por mastócitos bem diferenciados, com abundantes grânulos citoplasmáticos metacromáticos na coloração de Giemsa e infiltrado eosinofílico difuso. A imuno-histoquímica demonstrou que 30% das células neoplásicas eram positivas para a proteína Kit no citoplasma e na membrana celular. As células foram negativas para MAC e CD3. Menos de 10% das células neoplásicas foram positivas para Ki67. Durante a necropsia, foram identificados outros tumores primários, como adenoma intestinal, adenoma cortical da adrenal e tumor de células intersticiais do testículo.(AU)

Uso de técnica adaptada para cavotomia em cão com feocromocitoma associado a trombo neoplásico / Adapted cavotomy technique for pheochromocytoma associated tumor thrombi in a dog

Background: In dogs pheochromocytoma usually compress and invade into the adjacent vessels and structures, whichmay lead to the occurrence of caudal vena caval tumor thrombi. The surgical approach in these cases requires adrenalectomy with caval thrombectomy. Conventionally, tourniquets and partial occlusion clamp are used to reduce intraoperativeblood loss, but in dogs with a large thrombus associated to a great local tumor invasion, the traditional technique may behindered. The aim of this study was to report the use of a purse-string suture during venotomy of the caudal vena cava forthrombectomy, as an alternative to tourniquet and partial occlusion clamp.Case: An 11-year-old male Daschound breed dog, was referred for evaluation because of the appearance of small blackenednodules in the ventral abdomen. During a search for metastatic lesions with abdominal ultrasound, the right adrenal wasidentified with significant volume increase, and presence of tumor-associate circular formation that appeared to invade thecaudal vena cava, suggestive of neoplastic invasion or thrombus. Abdominal computed tomography showed caudal venacava in its hepatic portion presenting considerable increase in diameter, with caudal dilation and presence of hypoattenuatingmaterial in its lumen. Right adrenal gland with rounded appearance and regular borders, heterogeneous parenchyma andjuxtaposed caudal vena cava suggesting invasion of this, confirming the sonographic findings. During exploratory celiotomy,adherence of the adrenal mass to the right renal vessels and invasion of the caudal vena cava were observed, leading to theneed of nephrectomy and venotomy for thrombectomy. To perform the venotomy, a Rumel tourniquet was placed looselyaround the vena cava only caudal to the invasion point of the tumor thrombus, cranially, tourniquet application was notpossible due to the presence of a large thrombus extending into the intrahepatic cava...

Uso de técnica adaptada para cavotomia em cão com feocromocitoma associado a trombo neoplásico / Adapted cavotomy technique for pheochromocytoma associated tumor thrombi in a dog

Background: In dogs pheochromocytoma usually compress and invade into the adjacent vessels and structures, whichmay lead to the occurrence of caudal vena caval tumor thrombi. The surgical approach in these cases requires adrenalectomy with caval thrombectomy. Conventionally, tourniquets and partial occlusion clamp are used to reduce intraoperativeblood loss, but in dogs with a large thrombus associated to a great local tumor invasion, the traditional technique may behindered. The aim of this study was to report the use of a purse-string suture during venotomy of the caudal vena cava forthrombectomy, as an alternative to tourniquet and partial occlusion clamp.Case: An 11-year-old male Daschound breed dog, was referred for evaluation because of the appearance of small blackenednodules in the ventral abdomen. During a search for metastatic lesions with abdominal ultrasound, the right adrenal wasidentified with significant volume increase, and presence of tumor-associate circular formation that appeared to invade thecaudal vena cava, suggestive of neoplastic invasion or thrombus. Abdominal computed tomography showed caudal venacava in its hepatic portion presenting considerable increase in diameter, with caudal dilation and presence of hypoattenuatingmaterial in its lumen. Right adrenal gland with rounded appearance and regular borders, heterogeneous parenchyma andjuxtaposed caudal vena cava suggesting invasion of this, confirming the sonographic findings. During exploratory celiotomy,adherence of the adrenal mass to the right renal vessels and invasion of the caudal vena cava were observed, leading to theneed of nephrectomy and venotomy for thrombectomy. To perform the venotomy, a Rumel tourniquet was placed looselyaround the vena cava only caudal to the invasion point of the tumor thrombus, cranially, tourniquet application was notpossible due to the presence of a large thrombus extending into the intrahepatic cava...(AU)

Polimiopatia hipocalêmica e hipertensão secundária a hiperaldosteronismo primário felino / Hypokalemic polymyopathy and secondary hypertension to feline primary hyperaldosteronism

O hiperaldosteronismo se define pela hipersecreção de aldosterona pelas suprarrenais, resultando em excesso de sódio e redução de potássio sanguíneo. Esta hipersecreção deve-se à síntese autônoma de aldosterona por células adrenais hiperplásicas ou neoplásicas, que agem independentemente da estimulação pelo sistema renina-angiotensina. A doença acomete felinos de adultos maduros a idosos. O excesso de aldosterona culmina em hipertensão sistêmica e/ou hipocalemia, que levam à fraqueza muscular e alterações oculares. O diagnóstico é baseado em exames laboratoriais e de imagem, e o tratamento pode ser clínico ou cirúrgico. O prognóstico é considerado favorável quando as medicações são capazes de melhorar as manifestações clínicas ou quando é possível realizar o procedimento cirúrgico. O presente trabalho visa relatar o caso de um felino macho de 13 anos, castrado, sem raça definida, com hipocalemia persistente secundária a um presuntivo tumor adrenal.

Hyperaldosteronism is defined by the hypersecretion of aldosterone by the adrenal glands resulting in excess sodium and reduced blood potassium. This hypersecretion is due to the autonomous synthesis of aldosterone by hyperplastic or neoplastic adrenal cells, which act independently of stimulation by the renin-angiotensin system. The disease affects felines in the age group from mature adults to the elderly. The excess of aldosterone culminates in systemic hypertension and/or hypokalemia, which leads to muscle weakness and ocular changes. The diagnosis is based on laboratory and imaging tests and treatment can be clinical or surgical. The prognosis is considered favorable when the medications are able to improve the clinical manifestations or when it is possible to perform the surgical procedure. The present paper aims to report the case of a 13-year-old male cat, castrated, crossbred, with persistent hypokalemia secondary to a presumptive adrenal tumor.

Polimiopatia hipocalêmica e hipertensão secundária a hiperaldosteronismo primário felino / Hypokalemic polymyopathy and secondary hypertension to feline primary hyperaldosteronism

O hiperaldosteronismo se define pela hipersecreção de aldosterona pelas suprarrenais, resultando em excesso de sódio e redução de potássio sanguíneo. Esta hipersecreção deve-se à síntese autônoma de aldosterona por células adrenais hiperplásicas ou neoplásicas, que agem independentemente da estimulação pelo sistema renina-angiotensina. A doença acomete felinos de adultos maduros a idosos. O excesso de aldosterona culmina em hipertensão sistêmica e/ou hipocalemia, que levam à fraqueza muscular e alterações oculares. O diagnóstico é baseado em exames laboratoriais e de imagem, e o tratamento pode ser clínico ou cirúrgico. O prognóstico é considerado favorável quando as medicações são capazes de melhorar as manifestações clínicas ou quando é possível realizar o procedimento cirúrgico. O presente trabalho visa relatar o caso de um felino macho de 13 anos, castrado, sem raça definida, com hipocalemia persistente secundária a um presuntivo tumor adrenal.(AU)

Hyperaldosteronism is defined by the hypersecretion of aldosterone by the adrenal glands resulting in excess sodium and reduced blood potassium. This hypersecretion is due to the autonomous synthesis of aldosterone by hyperplastic or neoplastic adrenal cells, which act independently of stimulation by the renin-angiotensin system. The disease affects felines in the age group from mature adults to the elderly. The excess of aldosterone culminates in systemic hypertension and/or hypokalemia, which leads to muscle weakness and ocular changes. The diagnosis is based on laboratory and imaging tests and treatment can be clinical or surgical. The prognosis is considered favorable when the medications are able to improve the clinical manifestations or when it is possible to perform the surgical procedure. The present paper aims to report the case of a 13-year-old male cat, castrated, crossbred, with persistent hypokalemia secondary to a presumptive adrenal tumor.(AU)

Polimiopatia hipocalêmica e hipertensão secundária a hiperaldosteronismo primário felino / Hypokalemic polymyopathy and secondary hypertension to feline primary hyperaldosteronism

O hiperaldosteronismo se define pela hipersecreção de aldosterona pelas suprarrenais, resultando em excesso de sódio e redução de potássio sanguíneo. Esta hipersecreção deve-se à síntese autônoma de aldosterona por células adrenais hiperplásicas ou neoplásicas, que agem independentemente da estimulação pelo sistema renina-angiotensina. A doença acomete felinos de adultos maduros a idosos. O excesso de aldosterona culmina em hipertensão sistêmica e/ou hipocalemia, que levam à fraqueza muscular e alterações oculares. O diagnóstico é baseado em exames laboratoriais e de imagem, e o tratamento pode ser clínico ou cirúrgico. O prognóstico é considerado favorável quando as medicações são capazes de melhorar as manifestações clínicas ou quando é possível realizar o procedimento cirúrgico. O presente trabalho visa relatar o caso de um felino macho de 13 anos, castrado, sem raça definida, com hipocalemia persistente secundária a um presuntivo tumor adrenal.

Hyperaldosteronism is defined by the hypersecretion of aldosterone by the adrenal glands resulting in excess sodium and reduced blood potassium. This hypersecretion is due to the autonomous synthesis of aldosterone by hyperplastic or neoplastic adrenal cells, which act independently of stimulation by the renin-angiotensin system. The disease affects felines in the age group from mature adults to the elderly. The excess of aldosterone culminates in systemic hypertension and/or hypokalemia, which leads to muscle weakness and ocular changes. The diagnosis is based on laboratory and imaging tests and treatment can be clinical or surgical. The prognosis is considered favorable when the medications are able to improve the clinical manifestations or when it is possible to perform the surgical procedure. The present paper aims to report the case of a 13-year-old male cat, castrated, crossbred, with persistent hypokalemia secondary to a presumptive adrenal tumor.

Intravascular lymphoma in a dog: case report

Intravascular lymphoma is characterized by being a malignant neoplasm of extranodal T or B lymphocytes with exclusive proliferation within the vascular lumen, particularly of small vessels. The clinical signs vary due to the involvement of several organs, mainly the central nervous system. The diagnosis is difficult because many of the tests performed are not conclusive and, therefore, necropsy is the most efficient way to identify this tumor. This case report aims to describe the anatomopathological findings of a case of intravascular lymphoma in a mixed breed, 8 years old dog who presented neurological signs and was submitted to a necroscopic examination with clinical suspicion of granulomatous meningoencephalitis. The necropsy findings were not specific, but the presence of intravascular neoplastic lymphocytes int he brain, spleen, adrenal gland and stomach was verified by microscopy. These cells were positive for the CD3 antibody by immunohistochemistry, confirming the T lymphocyte phenotype. This neoplasm should be considered in the diagnosis of encephalopathies in dogs.(AU)

Intravascular lymphoma in a dog: case report

Intravascular lymphoma is characterized by being a malignant neoplasm of extranodal T or B lymphocytes with exclusive proliferation within the vascular lumen, particularly of small vessels. The clinical signs vary due to the involvement of several organs, mainly the central nervous system. The diagnosis is difficult because many of the tests performed are not conclusive and, therefore, necropsy is the most efficient way to identify this tumor. This case report aims to describe the anatomopathological findings of a case of intravascular lymphoma in a mixed breed, 8 years old dog who presented neurological signs and was submitted to a necroscopic examination with clinical suspicion of granulomatous meningoencephalitis. The necropsy findings were not specific, but the presence of intravascular neoplastic lymphocytes int he brain, spleen, adrenal gland and stomach was verified by microscopy. These cells were positive for the CD3 antibody by immunohistochemistry, confirming the T lymphocyte phenotype. This neoplasm should be considered in the diagnosis of encephalopathies in dogs.

Extranodal lymphoma in a bush dog (Speothos venaticus) - case report / Linfoma extranodal em um cachorro-do-mato-vinagre (Speothos venaticus) - relato de caso

A captive 7-year-old male bush dog (Speothos venaticus) was diagnosed with lymphoma affecting the kidneys, adrenal glands, liver, and spleen. The animal developed renal failure and was euthanized due to poor prognosis. Grossly, both kidneys were enlarged with multiple nodules. Histologically, the neoplasm was an infiltrative and poorly demarcated round cell tumor. Two morphologically distinct cell populations were observed, smaller cells with a lymphocytic morphology, and another population of larger and pleomorphic cells. Most of the smaller cell population, approximately 40% of the population within the neoplasm, were CD3 positive. Neoplastic cells were CD45, CD11d, and granzime B positive, and negative for CD20, CD79a, PAX5, CD163, and myeloperoxidase. This is the first reported case of lymphoma in a bush dog. This report demonstrated the suitability of several cell surface markers for differential diagnosis of round cell tumors in this species.(AU)

Um cachorro-do-mato-vinagre (Speothos venaticus), de sete anos de idade, mantido em cativeiro, foi diagnosticado com linfoma que havia afetado os rins, as adrenais, o fígado e o baço. O animal desenvolveu insuficiência renal e foi submetido à eutanásia devido ao prognóstico desfavorável. Macroscopicamente, ambos os rins estavam aumentados de tamanho, com múltiplos nódulos. Histologicamente, a neoplasia era infiltrativa, pobremente delimitada e constituída por células redondas. Duas populações distintas foram observadas: células pequenas com morfologia linfocítica e células grandes e pleomórficas. A maior parte da população de células pequenas, correspondendo a aproximadamente 40% da população celular na neoplasia, foi positiva para CD3. As células neoplásicas foram positivas para CD45, CD11d e granzima B e negativas para CD20, CD79a, PAX5, CD163 e mieloperoxidase. Este é o primeiro caso de linfoma em um cachorro-do-mato-vinagre. Tal relado demonstra a utilidade de vários marcadores de superfície celular para o diagnóstico diferencial de tumores de células redondas nessa espécie.(AU)

Extranodal lymphoma in a bush dog (Speothos venaticus) - case report / Linfoma extranodal em um cachorro-do-mato-vinagre (Speothos venaticus) - relato de caso

A captive 7-year-old male bush dog (Speothos venaticus) was diagnosed with lymphoma affecting the kidneys, adrenal glands, liver, and spleen. The animal developed renal failure and was euthanized due to poor prognosis. Grossly, both kidneys were enlarged with multiple nodules. Histologically, the neoplasm was an infiltrative and poorly demarcated round cell tumor. Two morphologically distinct cell populations were observed, smaller cells with a lymphocytic morphology, and another population of larger and pleomorphic cells. Most of the smaller cell population, approximately 40% of the population within the neoplasm, were CD3 positive. Neoplastic cells were CD45, CD11d, and granzime B positive, and negative for CD20, CD79a, PAX5, CD163, and myeloperoxidase. This is the first reported case of lymphoma in a bush dog. This report demonstrated the suitability of several cell surface markers for differential diagnosis of round cell tumors in this species.(AU)

Um cachorro-do-mato-vinagre (Speothos venaticus), de sete anos de idade, mantido em cativeiro, foi diagnosticado com linfoma que havia afetado os rins, as adrenais, o fígado e o baço. O animal desenvolveu insuficiência renal e foi submetido à eutanásia devido ao prognóstico desfavorável. Macroscopicamente, ambos os rins estavam aumentados de tamanho, com múltiplos nódulos. Histologicamente, a neoplasia era infiltrativa, pobremente delimitada e constituída por células redondas. Duas populações distintas foram observadas: células pequenas com morfologia linfocítica e células grandes e pleomórficas. A maior parte da população de células pequenas, correspondendo a aproximadamente 40% da população celular na neoplasia, foi positiva para CD3. As células neoplásicas foram positivas para CD45, CD11d e granzima B e negativas para CD20, CD79a, PAX5, CD163 e mieloperoxidase. Este é o primeiro caso de linfoma em um cachorro-do-mato-vinagre. Tal relado demonstra a utilidade de vários marcadores de superfície celular para o diagnóstico diferencial de tumores de células redondas nessa espécie.(AU)

Carcinoma adrenocortical incidental em cão: aspectos clínicos, tomográficos e histopatológicos / Incidental adrenocortical carcinoma in dog: clinical, tomographic and histopathological aspects

Background: Adrenal incidentalomas are masses accidentally discovered during imaging examinations performed whenthere is no suspicion of adrenal disease. Even with a low prevalence, it is important to perform a reliable evaluation observing biological behavior and determining whether the hormonal activity is stimulated. Frequently, these masses are notfunctional, but in some cases, there is increased cortisol activity, and patients with adrenal incidentalomas may presenthyperadrenocorticism. This report aims to describe the clinical, tomographic, and histopathological aspects of a case ofadrenal incidentaloma detected in a routine abdominal ultrasound.Case: An 8-year-old, male, maltese dog with occasional emesis, halitosis, claudication of the left pelvic limb, and previous compensated and untreated cardiomyopathy was treated at the Veterinary Hospital of the Federal University of MatoGrosso (HOVET-UFMT). Physical examination revealed arterial hypertension and claudication, with the positive posteriordrawer test suggesting rupture of the cruciate ligament. The blood count showed no alteration, and the serum biochemistryrevealed a slight increase in the activity of alanine aminotransferase. In order to investigate this increase, an abdominalultrasound was performed. Slight hepatomegaly and a heterogeneous mass of irregular edges were observed with a moderate and difficult-to-delimit vascularization of the adrenal gland. Left knee radiography raised the suspicion of rupture ofthe cranial cruciate ligament due to the cranial displacement of the tibia in relation to the femur. Computed tomographywas performed to define the extent and delimitation of the mass, which was compatible with a tumor of the right adrenalgland characterized by the visualization of an abdominal mass...(AU)

Carcinoma adrenocortical incidental em cão: aspectos clínicos, tomográficos e histopatológicos / Incidental adrenocortical carcinoma in dog: clinical, tomographic and histopathological aspects

Background: Adrenal incidentalomas are masses accidentally discovered during imaging examinations performed whenthere is no suspicion of adrenal disease. Even with a low prevalence, it is important to perform a reliable evaluation observing biological behavior and determining whether the hormonal activity is stimulated. Frequently, these masses are notfunctional, but in some cases, there is increased cortisol activity, and patients with adrenal incidentalomas may presenthyperadrenocorticism. This report aims to describe the clinical, tomographic, and histopathological aspects of a case ofadrenal incidentaloma detected in a routine abdominal ultrasound.Case: An 8-year-old, male, maltese dog with occasional emesis, halitosis, claudication of the left pelvic limb, and previous compensated and untreated cardiomyopathy was treated at the Veterinary Hospital of the Federal University of MatoGrosso (HOVET-UFMT). Physical examination revealed arterial hypertension and claudication, with the positive posteriordrawer test suggesting rupture of the cruciate ligament. The blood count showed no alteration, and the serum biochemistryrevealed a slight increase in the activity of alanine aminotransferase. In order to investigate this increase, an abdominalultrasound was performed. Slight hepatomegaly and a heterogeneous mass of irregular edges were observed with a moderate and difficult-to-delimit vascularization of the adrenal gland. Left knee radiography raised the suspicion of rupture ofthe cranial cruciate ligament due to the cranial displacement of the tibia in relation to the femur. Computed tomographywas performed to define the extent and delimitation of the mass, which was compatible with a tumor of the right adrenalgland characterized by the visualization of an abdominal mass...

A case of orbital extra-adrenal paraganglioma in a quarter horse

Paragangliomas are tumors originating from paraganglia cells which represent a considerable constituent of the dispersed neuroendocrine system. Rarely these tumors are found within the orbital region. This report documents a case of primary extra-adrenal paraganglioma in a 15-year-old female quarter horse, diagnosed on the basis of clinical signs, gross anatomopathological, histopathological and immunohistochemical investigations. Clinical diagnostics led to full appreciation of the severe tumor invasiveness and to an informed decision by the owner for euthanasia. Gross inspection confirmed the previous clinical assessments of exophthalmos consequential to pressure from the orbital neoplasia, revealing a mass infiltrating into surrounding tissues. Histopathology and immunohistochemistry allowed for the final diagnosis of paraganglioma. Histology sections showed a partially encapsulated infiltrative mass with multifocal angiotropic growth, and composed of polygonal cells organized in nests, packets, and bundles supported by a fibrovascular stroma. The lobules were lined peripherally by spindle cells. The tumor was highly vascular with blood-filled lacunae and multifocal to coalescing areas of liquefactive necrosis. The polygonal cells were characterized by indistinct borders, lightly eosinophilic cytoplasm with moderate amount of granules, round or oval central nuclei with stippled chromatin (“salt and pepper” appearance) and inconspicuous nucleoli. Immunohistochemistry aided in the diagnostic discrimination of paraganglioma from neuroendocrine carcinoma and in the assessment of tumor differentiation. Orbital paraganglioma holds low likelihood for animal survival, but may have good prognosis when timely addressed.