Collagenous choristoma at the cerebellar peduncle of a Nelore bull

Abstract

Choristomas are mature normal tissues in abnormal anatomical positions. Reports in domestic animals are uncommon to rare, usually restricted to cattle, with the proliferation of different tissues in various locations, such as subcutaneous tissue, thoracic cavity, retroperitoneal and ocular regions. No age range is predominantly affected, but there are more reports in young cattle. The Laboratory of Veterinary Pathology at the Universidade Federal do Rio Grande do Sul received a brainstem sample of a bull, Nelore breed, 5 years old, from the project of Supplementary Diagnostic Methods of Transmissible Spongiform Encephalopathies (TSEs). The animal presented recumbency at the time of slaughter; was alert, with a complete fracture to the right femur and without neurological signs. On gross examination, there was a white oval firm mass, located caudally to the left caudal colliculus, on the left cerebellar peduncle. In the microscopic examination, there was a well-demarcated area, unencapsulated and composed predominantly of connective tissue fibers (collagen). Immunohistochemical examination for glial fibrillary acidic protein was negative. Due to the gross and microscopic characteristics, a diagnosis of collagenous choristoma at the cerebellar peduncle was established, since the presence of collagen within the brain tissue itself is abnormal. Key words: Brain, ruminant, tumor-like lesions ResumoCoristomas são tecidos normais maduros em posições anatômicas anormais. Relatos em animais domésticos são incomuns a raros, restringindo-se geralmente à espécie bovina, com proliferação de diferentes tecidos em várias localizações, como tecido subcutâneo, cavidade torácica, região retroperitoneal e ocular. Não há uma faixa etária predominantemente afetada, porém há mais relatos em bovinos jovens. O Laboratório de Patologia Veterinária da Universidade Federal do Rio Grande do Sul recebeu uma amostra de tronco encefálico de um bovino Nelore, macho, cinco anos de idade, vinculado ao projeto de Complementação de Métodos Diagnósticos de Encefalopatias Espongiformes Transmissíveis (EETs). O animal apresentava-se no momento do abate em decúbito; estava alerta, com uma fratura completa no fêmur direito e sem sinais neurológicos. No exame macroscópico, observou-se uma massa branca oval, firme, localizada caudalmente ao colículo caudal esquerdo, sobre o pedúnculo cerebelar esquerdo. No exame microscópico, observou-se uma área bem delimitada, não encapsulada, composta predominantemente por fibras de tecido conjuntivo fibroso (colágeno). O exame imuno-histoquímico para proteína ácida fibrilar glial foi negativo. Devido às características macroscópicas e microscópicas, o diagnóstico de coristoma colagenoso foi estabelecido, visto que a presença de colágeno no encéfalo é anormal.

Muscular and collagenous cerebellar choristoma in a dog

“…It is believed that the choristoma in the patient's cerebellum in our report was not the cause of the patient’s clinical signs, as it was probably present throughout the dog’s life and was incidentally discovered on necropsy. Similarly, the only case of collagenous choristoma in the cerebellum described in veterinary literature was found in a 5-yr-old cow that also did not present with neurological alterations [ 2 ].…”

“…In light of the macroscopic and microscopic findings of the lesion, a diagnosis of muscular and collagenous choristoma was established, as the presence of collagen in the brain parenchyma is abnormal [ 2 ]. Furthermore, on microscopy, the tissues observed were distinguished from neoplastic or metastatic lesions because of the well-differentiated appearance of the ectopic tissue.…”

“…Choristoma is the ectopic presence of histologically normal tissues [ 1 ]. Although it is an uncommon condition encountered in veterinary medicine, it is reported to affect all species of domestic animals and known to involve a number of different organs [ 1 2 ].…”

“…In humans, there are a few reported cases of choristoma, mostly occurring in the nervous system, with preferential involvement of the peripheral nerves [ 3 ]. There is one reported case of collagenous choristoma in a bovine, till date [ 2 ], however, there are no known reports describing similar lesions in the cerebellum of humans [ 4 ] or dogs.…”

Pulmonary choristoma in a new-born calf with multiple cranial and nervous malformations

“…location (ChAUvet et al, 1994;BiAnChi et al, 2015). Conversely, hydrocephalus is characterized by abnormal accumulation of fluid in the cranial cavity, while cranioschisis is defined as failure in the fusion of cranial bones (CAntile & yOUsseF, 2016).…”