Meningothelial meningioma in a Malayan sun bear (Helarctos malayanus).
A 24-year-old, spayed female Malayan sun bear (Helarctos malayanus) in the Taipei Zoo (Taipei, Taiwan) showed clinical signs of slowly progressive anorexia, dullness, compulsive pacing, and circling. The animal subsequently developed acute severe stupor and persistent recumbency. Postcontrast study of computed tomography revealed a spheroid, extra-axial mass with strong but heterogeneous hyperattenuation in the left temporal lobe of the cerebrum. At necropsy, a solitary, well-circumscribed intracranial mass measuring 3 cm × 2.5 cm × 2 cm was attached to the left pyriform lobe with compression of the adjacent neuroparenchyma. Cytological examination obtained from the mass revealed large clumps and sheets of cohesive polyhedral cells with round nuclei, wispy cytoplasm, and indistinct cell borders. Microscopically, the mass was composed of densely packed round to polygonal cells arranged in lobules and small nests. Psammoma bodies, xanthomatous change, and cholesterol deposition were also noted. Immunohistochemical staining of the tumor was positive for vimentin, pancytokeratin, cytokeratin (CK)34BE12, neuron-specific enolase, and epithelial membrane antigen, but negative for glial fibrillary acidic protein and S100 protein. The cytological, histological, and immunohistochemical features were compatible with a meningothelial meningioma.
1Chen-Hsuan Liu, Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, No. 1 Section 4, Roosevelt Road, Taipei 106, Taiwan. chhsuliu@ntu.edu.tw.
Yao-Chun
YC
Chien
Chen-Yeh
CY
Lien
Jun-Cheng
JC
Guo
Shih-Chien
SC
Chin
Ya-Pei
YP
Chang
Chen-Hsuan
CH
Liu
D000818:Animals; D000836:Animals, Zoo; D005260:Female; D006651:Histocytochemistry / Q000662:veterinary; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D008579:Meningioma / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D011859:Radiography; D013624:Taiwan; D001503:Ursidae
Bears; brain; meningioma