Nasal leiomyosarcoma in a Quarter Horse / Leiomiossarcoma nasal em equino Quarto de Milha

ABSTRACT: We described the clinical and anatomopathological findings observed in a case of nasal leiomyosarcoma in a five-year-old male Quarter Mile horse, whose main complaints were decreased sports performance and bilateral purulent nasal discharge. The nodule was observed in the nasal cavity, obstructing the left nostril and associated with purulent drainage. The nodule was of irregular shape and yellow color, measuring 19.4 cm × 6.9 cm × 4.3 cm in size, with coalescent multifocal areas that were brownish, friable, opaque, and fetid. When cut, the surface was compact, grayish-white, and smooth with yellow, friable, irregular multifocal areas, measuring 1-3.2 cm in diameter. Histopathological examination showed spindle-shaped neoplastic cells, which was negative on Masson's trichromic stain. A diagnosis of leiomyosarcoma was established based on the morphotintorial aspects of neoplastic cells and confirmed through immunohistochemistry, with positive immunostaining for antibodies 1A4, HHF35, desmin, and S100. Leiomyosarcoma primarily affects the nasal cavity of horses and should be included in the differential diagnosis of diseases that affect the nasal cavity and cause nasal obstruction associated with dyspnea.

RESUMO: Descreve-se os achados clínicos e anatomopatológicos observados em um caso de leiomiossarcoma nasal em um equino, Quarto de Milha, macho, de cinco anos de idade, com queixa principal de diminuição do rendimento esportivo e secreção nasal purulenta bilateral. Na cavidade nasal, observou-se um nódulo obstruindo a narina esquerda associada à secreção purulenta. O nódulo era de superfície irregular, amarelada, brilhante, fibroelástica, medindo 19,4 x 6,9 x 4,3cm de tamanho, com áreas multifocais a coalescente acastanhadas, friáveis, opacas e fétidas. Ao corte, a superfície era compacta, branco-acinzentada e lisa com áreas multifocais amarelas, friáveis e irregulares, medindo 1-3,2 cm de diâmetro. No exame histopatológico foi observado proliferação de células neoplásicas fusiformes, que foram negativas na coloração de Tricrômico de Masson. O diagnóstico de leiomiossarcoma foi estabelecido com base nos aspectos morfotintoriais das células neoplásicas e confirmado através da imuno-histoquímica, no qual houve imunomarcação positiva para os anticorpos 1A4, HHF35, Desmina e S100. O leiomiossarcoma pode afetar primariamente a cavidade nasal de equinos, devendo ser incluído no diagnóstico diferencial de doenças que afetam a cavidade nasal e que provocam quadros de obstrução nasal associado a dispneia.

Nasal leiomyosarcoma in a Quarter Horse / Leiomiossarcoma nasal em equino Quarto de Milha

We described the clinical and anatomopathological findings observed in a case of nasal leiomyosarcoma in a five-year-old male Quarter Mile horse, whose main complaints were decreased sports performance and bilateral purulent nasal discharge. The nodule was observed in the nasal cavity, obstructing the left nostril and associated with purulent drainage. The nodule was of irregular shape and yellow color, measuring 19.4 cm × 6.9 cm × 4.3 cm in size, with coalescent multifocal areas that were brownish, friable, opaque, and fetid. When cut, the surface was compact, grayish-white, and smooth with yellow, friable, irregular multifocal areas, measuring 1-3.2 cm in diameter. Histopathological examination showed spindle-shaped neoplastic cells, which was negative on Masson's trichromic stain. A diagnosis of leiomyosarcoma was established based on the morphotintorial aspects of neoplastic cells and confirmed through immunohistochemistry, with positive immunostaining for antibodies 1A4, HHF35, desmin, and S100. Leiomyosarcoma primarily affects the nasal cavity of horses and should be included in the differential diagnosis of diseases that affect the nasal cavity and cause nasal obstruction associated with dyspnea.

Descreve-se os achados clínicos e anatomopatológicos observados em um caso de leiomiossarcoma nasal em um equino, Quarto de Milha, macho, de cinco anos de idade, com queixa principal de diminuição do rendimento esportivo e secreção nasal purulenta bilateral. Na cavidade nasal, observou-se um nódulo obstruindo a narina esquerda associada à secreção purulenta. O nódulo era de superfície irregular, amarelada, brilhante, fibroelástica, medindo 19,4 x 6,9 x 4,3cm de tamanho, com áreas multifocais a coalescente acastanhadas, friáveis, opacas e fétidas. Ao corte, a superfície era compacta, branco-acinzentada e lisa com áreas multifocais amarelas, friáveis e irregulares, medindo 1-3,2 cm de diâmetro. No exame histopatológico foi observado proliferação de células neoplásicas fusiformes, que foram negativas na coloração de Tricrômico de Masson. O diagnóstico de leiomiossarcoma foi estabelecido com base nos aspectos morfotintoriais das células neoplásicas e confirmado através da imuno-histoquímica, no qual houve imunomarcação positiva para os anticorpos 1A4, HHF35, Desmina e S100. O leiomiossarcoma pode afetar primariamente a cavidade nasal de equinos, devendo ser incluído no diagnóstico diferencial de doenças que afetam a cavidade nasal e que provocam quadros de obstrução nasal associado a dispneia.

Mastite por Pythium insidiosum em éguas / Mastitis by Pythium insidiosum in mares

Background: Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum. This disease hasbeen reported in several species, but most cases occur in horses. In this species, the cutaneous form is more prevalent,with occasional involvement of adjacent lymph nodes and bone tissue. The involvement of the mammary glands was notproperly characterized. Therefore, the aim of this study is to describe cases of pythiosis with the involvement of the mammary glands in mares.Case: A retrospective study of all biopsy samples and necropsy examinations of horses, performed at the Animal PathologyLaboratory of the Federal University of Campina Grande from January 2000 to December 2018, was carried out. During thestudy period, 142 cases of cutaneous pythiosis were identified. Of these, in three the lesions extended to the mammary glands.Mares with 3-, 7- and 12-year-old, mongrel, from the backlands of the Paraiba were affected. On physical examination, themares presented swollen mammary glands and multifocal wounds, which discharge serosanguinolent secretion. Clinicalevolution ranged from 15 to 30 days. The animals had been medicated, but the wounds did not heal and mastectomies wereperformed. Macroscopically, the mammary glands were enlarged and with multifocal areas of ulceration measuring 1 to 3.5cm in diameter. At the cut surface, they exhibited fistulous tracts containing kunkers. In the histopathological evaluation,was observed diffuse and marked inflammatory infiltrate of eosinophils extending through the deep dermis and interlobularmammary stroma; and multifocal areas, sometimes focally extensive, of eosinophilic necrosis with intralesional negativeimages of hyphae. In histological sections stained by periodic acid-Schiff, the walls of the hyphae were weakly stained inblue; but when impregnated by Grocott methenamine silver, they were strongly marked in black...(AU)

Mastite por Pythium insidiosum em éguas / Mastitis by Pythium insidiosum in mares

Background: Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum. This disease hasbeen reported in several species, but most cases occur in horses. In this species, the cutaneous form is more prevalent,with occasional involvement of adjacent lymph nodes and bone tissue. The involvement of the mammary glands was notproperly characterized. Therefore, the aim of this study is to describe cases of pythiosis with the involvement of the mammary glands in mares.Case: A retrospective study of all biopsy samples and necropsy examinations of horses, performed at the Animal PathologyLaboratory of the Federal University of Campina Grande from January 2000 to December 2018, was carried out. During thestudy period, 142 cases of cutaneous pythiosis were identified. Of these, in three the lesions extended to the mammary glands.Mares with 3-, 7- and 12-year-old, mongrel, from the backlands of the Paraiba were affected. On physical examination, themares presented swollen mammary glands and multifocal wounds, which discharge serosanguinolent secretion. Clinicalevolution ranged from 15 to 30 days. The animals had been medicated, but the wounds did not heal and mastectomies wereperformed. Macroscopically, the mammary glands were enlarged and with multifocal areas of ulceration measuring 1 to 3.5cm in diameter. At the cut surface, they exhibited fistulous tracts containing kunkers. In the histopathological evaluation,was observed diffuse and marked inflammatory infiltrate of eosinophils extending through the deep dermis and interlobularmammary stroma; and multifocal areas, sometimes focally extensive, of eosinophilic necrosis with intralesional negativeimages of hyphae. In histological sections stained by periodic acid-Schiff, the walls of the hyphae were weakly stained inblue; but when impregnated by Grocott methenamine silver, they were strongly marked in black...