Medulloblastoma in a calf of the flemish breed / Meduloblastoma em bezerro da raça Flamenga

Medulloblastomas are neuroectodermal tumors of embryonic origin developing in cerebellum and spinal cord and have an unusual occurrence. When occurs in cattle, it is observed in neonatal cases, leading to multiple neurological clinical signs. Flemish cattle are considered at risk of extinction and the rare specimens of Brazil are in Lages, Santa Catarina. The case of a two-month-old calf with difficulty to remain in a standing position, imbalance, opisthotonus, strabismus, and broad-based gait is described in this study. The animal was euthanized and the necropsy showed an irregular, whitish pink, and friable mass in the cerebellar vermis region, measuring 5×6×3.8 cm associated with the dilation of the lateral ventricles, which extended through the interventricular foramen, midbrain aqueduct, and fourth ventricle. Histologically, it presented elongated triangular neuronal cells arranged in a dense sheet that sometimes encircled small areas of neuropil to form Homer-Wright pseudorosettes. These tumor characteristics were compatible with a medulloblastoma. The immunohistochemical (IHC) evaluation of the tumor demonstrated a positive staining for vimentin in neoplastic cells and glial fibrillary acidic protein in neoplastic stromal cells, non-reactive for synaptophysin, and negative for S100 protein and pan-cytokeratin. The histological and topographical characteristics were paramount for determining the medulloblastoma diagnosis and the IHC panl is similar to that observed in other studies. Tumor growth is limited by skull bony structures, allowing determining that the clinical signs expressed by the animal were directly related to the compression of important functional structures due to tumor expansion. Medulloblastoma is an unusual tumor in all animal species, not previously reported in Flemish cattle, and necropsy followed by histopathological examination is essential for diagnosis.(AU)

Meduloblastomas são tumores da neuroectoderme com origem embrionária, que se desenvolvem no cerebelo e na medula espinhal com ocorrência incomum. Quando ocorre em bovinos é observado em casos neonatal, levando a múltiplos sinais clínicos neurológicos. Os bovinos da raça Flamenga estão considerados em risco de extinção e os raros exemplares do Brasil estão localizados em Lages, Santa Catarina. Descreve-se o caso de um bezerro com dois meses de idade, apresentando dificuldade para manter-se em estação, desequilíbrio, opistótono, estrabismo e caminhar em base ampla. O animal foi submetido a eutanásia e na necropsia observou-se na região do vérmis do cerebelo uma massa irregular, rosa esbranquiçada e friável, medindo 5x6x3,8cm associado a dilatação dos ventrículos laterais, que prolongava pelo forame interventricular, aqueduto do mesencéfalo e IV ventrículo. Histologicamente, observava células neuronais triangulares alongadas organizadas em um lençol denso, que às vezes circundavam pequenas áreas de neurópilo para formar pseudorosetas de Homer-Wright, estas características do tumor eram compatíveis com um meduloblastoma. A avaliação imuno-histoquímica (IHQ) do tumor demonstrou marcação positiva para vimentina em células neoplásicas e para proteína glial fibrilar ácida em células do estroma neoplásico, não reagente para sinaptofisina e negativo para proteína S100 e pan-citoqueratina. As características histológicas e topográficas foram primordiais para a determinação do diagnóstico de meduloblastoma e o painel IHQ é semelhante à observada em outros trabalhos. O crescimento do tumor é limitado pelas estruturas ósseas do crânio, permitindo determinar que os sinais clínicos expressos pelo animal estavam diretamente relacionados com a compressão de estruturas funcionais importantes em decorrência da expansão tumoral.(AU)

Medulloblastoma in a calf of the flemish breed / Meduloblastoma em bezerro da raça Flamenga

Medulloblastomas are neuroectodermal tumors of embryonic origin developing in cerebellum and spinal cord and have an unusual occurrence. When occurs in cattle, it is observed in neonatal cases, leading to multiple neurological clinical signs. Flemish cattle are considered at risk of extinction and the rare specimens of Brazil are in Lages, Santa Catarina. The case of a two-month-old calf with difficulty to remain in a standing position, imbalance, opisthotonus, strabismus, and broad-based gait is described in this study. The animal was euthanized and the necropsy showed an irregular, whitish pink, and friable mass in the cerebellar vermis region, measuring 5×6×3.8 cm associated with the dilation of the lateral ventricles, which extended through the interventricular foramen, midbrain aqueduct, and fourth ventricle. Histologically, it presented elongated triangular neuronal cells arranged in a dense sheet that sometimes encircled small areas of neuropil to form Homer-Wright pseudorosettes. These tumor characteristics were compatible with a medulloblastoma. The immunohistochemical (IHC) evaluation of the tumor demonstrated a positive staining for vimentin in neoplastic cells and glial fibrillary acidic protein in neoplastic stromal cells, non-reactive for synaptophysin, and negative for S100 protein and pan-cytokeratin. The histological and topographical characteristics were paramount for determining the medulloblastoma diagnosis and the IHC panl is similar to that observed in other studies. Tumor growth is limited by skull bony structures, allowing determining that the clinical signs expressed by the animal were directly related to the compression of important functional structures due to tumor expansion. Medulloblastoma is an unusual tumor in all animal species, not previously reported in Flemish cattle, and necropsy followed by histopathological examination is essential for diagnosis.

Meduloblastomas são tumores da neuroectoderme com origem embrionária, que se desenvolvem no cerebelo e na medula espinhal com ocorrência incomum. Quando ocorre em bovinos é observado em casos neonatal, levando a múltiplos sinais clínicos neurológicos. Os bovinos da raça Flamenga estão considerados em risco de extinção e os raros exemplares do Brasil estão localizados em Lages, Santa Catarina. Descreve-se o caso de um bezerro com dois meses de idade, apresentando dificuldade para manter-se em estação, desequilíbrio, opistótono, estrabismo e caminhar em base ampla. O animal foi submetido a eutanásia e na necropsia observou-se na região do vérmis do cerebelo uma massa irregular, rosa esbranquiçada e friável, medindo 5x6x3,8cm associado a dilatação dos ventrículos laterais, que prolongava pelo forame interventricular, aqueduto do mesencéfalo e IV ventrículo. Histologicamente, observava células neuronais triangulares alongadas organizadas em um lençol denso, que às vezes circundavam pequenas áreas de neurópilo para formar pseudorosetas de Homer-Wright, estas características do tumor eram compatíveis com um meduloblastoma. A avaliação imuno-histoquímica (IHQ) do tumor demonstrou marcação positiva para vimentina em células neoplásicas e para proteína glial fibrilar ácida em células do estroma neoplásico, não reagente para sinaptofisina e negativo para proteína S100 e pan-citoqueratina. As características histológicas e topográficas foram primordiais para a determinação do diagnóstico de meduloblastoma e o painel IHQ é semelhante à observada em outros trabalhos. O crescimento do tumor é limitado pelas estruturas ósseas do crânio, permitindo determinar que os sinais clínicos expressos pelo animal estavam diretamente relacionados com a compressão de estruturas funcionais importantes em decorrência da expansão tumoral.

Medulloblastoma in a Calf: Case Report

A two-month-old calf was presented to the Bovine Clinic of the Universidade Federal Rural de Pernambuco, Campus Garanhuns (Brazil), with a history of lack of motor coordination in the hind limbs, progressing toward laterally inclined ambulation and imbalance since birth. The recent onset of daily seizures left the calf unable to stand. The animal exhibited pedaling movements and salivation. During the clinical exam, the calf was in lateral recumbency, with hyperextension of the fore and hind limbs, myoclonus, intention tremors (mainly of the head), opisthotonus and nystagmus. The signs were exacerbated upon stimulation. Anus and tail reflexes were diminished. The blood count findings were non-specific. The necropsy revealed a whitish, friable mass with an irregular contour affecting the surface and interior of the cerebellum and brain stem, with the left cerebellar hemisphere more affected. The lateral ventricles (mainly the left ventricle) were dilated and herniation of the cerebellum through the magnum foramen was observed. The diagnosis of medulloblastoma was performed based on the anatomical location and histopathological characteristics of the tumor.

Medulloblastoma in a Calf: Case Report

A two-month-old calf was presented to the Bovine Clinic of the Universidade Federal Rural de Pernambuco, Campus Garanhuns (Brazil), with a history of lack of motor coordination in the hind limbs, progressing toward laterally inclined ambulation and imbalance since birth. The recent onset of daily seizures left the calf unable to stand. The animal exhibited pedaling movements and salivation. During the clinical exam, the calf was in lateral recumbency, with hyperextension of the fore and hind limbs, myoclonus, intention tremors (mainly of the head), opisthotonus and nystagmus. The signs were exacerbated upon stimulation. Anus and tail reflexes were diminished. The blood count findings were non-specific. The necropsy revealed a whitish, friable mass with an irregular contour affecting the surface and interior of the cerebellum and brain stem, with the left cerebellar hemisphere more affected. The lateral ventricles (mainly the left ventricle) were dilated and herniation of the cerebellum through the magnum foramen was observed. The diagnosis of medulloblastoma was performed based on the anatomical location and histopathological characteristics of the tumor.(AU)