Choroid Plexus Cyst in a Neonatal Burmeister's Porpoise (Phocoena spinipinnis)

Neuroectodermal developmental anomalies are reported rarely in cetaceans and central nervous system cysts are not described. We describe the gross, microscopical, histochemical and immunohistochemical features of a neuraxial myelencephalic cyst in a stranded neonatal Burmeister's porpoise (Phocoena spinipinnis). Grossly, a subdural, extra-axial, well-demarcated, yellow fluid-filled cystic structure (1.9 × 1.6 × 1 cm) expanded the left foramen of Luschka, the left caudolateral cerebellar recess and the left cranioventral myelencephalon. The cyst displaced the ipsilateral ventral paraflocculus and distended the underlying cranial nerves IX, X, XI and XII. Microscopically, the cystic structure was lined by a monolayer of low cuboidal to flattened epithelium supported by a thin fibrovascular matrix. Immunohistochemistry (IHC) revealed strong and diffuse expression of AE1/AE3 and focal positivity for vimentin. IHC for epithelial membrane antigen, glial fibrillary acid protein, synaptophysin and S100 was negative. Based on these findings, an extra-axial cyst of the choroid plexus of the fourth ventricle (CCPFV) was diagnosed. The pathological relevance of the CCPFV in this case is uncertain. The cause of death involved severe perinatal interspecific (shark) trauma. The present case provides the first evidence of a neuroepithelial cyst in cetacean species.

anomalias de desenvolvimento neuroectodérmicas são raramente relatadas em cetáceos e cistos do sistema nervoso central não são descritos. Descrevemos as características macroscópicas, microscópicas, histoquímicas e imuno-histoquímicas de um cisto mielencefálico neuroaxial em uma toninha de Burmeister neonatal encalhada (Phocoena spinipinnis). Grosso modo, uma estrutura cística amarela subdural, extra-axial, bem demarcada e cheia de líquido (1,9 × 1,6 × 1 cm) expandiu o forame esquerdo de Luschka, o recesso cerebelar caudolateral esquerdo e o mielencéfalo cranioventral esquerdo. O cisto deslocou o paraflóculo ventral ipsilateral e distendeu os nervos cranianos subjacentes IX, X, XI e XII. Microscopicamente, a estrutura cística foi revestida por uma monocamada de epitélio cubóide a achatado baixo, suportada por uma fina matriz fibrovascular. A imuno-histoquímica (IHC) revelou forte e difusa expressão de AE1 / AE3 e positividade focal para vimentina. O IHC para antígeno da membrana epitelial, proteína do ácido fibrilar glial, sinafofisina e S100 foi negativo. Com base nesses achados, foi diagnosticado um cisto extra-axial do plexo coróide do quarto ventrículo (CCPFV). A relevância patológica do CCPFV neste caso é incerta. A causa da morte envolveu traumatismo interespecífico (tubarão) perinatal grave. O presente caso fornece a primeira evidência de um cisto neuroepitelial em espécies de cetáceos. patologia cetáceo Anomalia congenita neuroectoderma

Lacaziosis-like disease in Tursiops truncatus from Brazil: a histopathological and immunohistochemical approach

ABSTRACT: Cetacean lacaziosis-like disease or lobomycosis-like disease (LLD) is a chronic skin condition caused by a non-cultivable yeast of the order Onygenales, which also includes Lacazia loboi, as well as Paracoccidioides brasiliensis and P. lutzii, respectively responsible for lacaziosis and paracoccidioidomycosis in humans. Complete identification and phylogenetic classification of the LLD etiological agent still needs to be elucidated, but preliminary phylogenetic analyses have shown a closer relationship of the LLD agent to Paracoccidioides spp. than to L. loboi. Cases of LLD in South American cetaceans based on photographic identification have been reported; however, to date, only 3 histologically confirmed cases of LLD have been described. We evaluated multiple tissue samples from 4 Tursiops truncatus stranded in the states of Santa Catarina (n = 3) and Rio Grande do Sul (n = 1), southern Brazil. Macroscopically, all animals presented lesions consistent with LLD. Hematoxylin-eosin, periodic acid-Schiff, Grocott's methenamine silver, and Mayer's mucicarmin stains were used for histological evaluation. Microscopically, numerous refractile yeasts (4-9 µm in diameter) were observed in skin samples (4/4), and for the first time in dolphins, also in a skeletal muscle abscess (1/4). Immunohistochemistry using anti-P. brasiliensis glycoprotein gp43 as a primary antibody, which is known to cross-react with L. loboi and the LLD agent, was performed and results were positive in all 4 cases. We describe 3 new cases of LLD in cetaceans based on histopathology and immunohistochemistry. This is the first report of LLD in the muscle of cetaceans.