Fibro-osseous lesion of the pineal region resembling osteoblastoma: a case report.

A case of unusual fibro-osseous lesion resembling osteoblastoma of the pineal region is reported, in a 50-year-old man. The patient presented with a history of headache, vomiting and generalized tonic-clonic seizures. CT scan showed a hyperdense lesion in the posterior third ventricle with obstructive hydrocephalus. On histopathology the lesion showed cellular areas with oval to polygonal cells showing clear to eosinophilic cytoplasm along with focal anastomosing network of osetoid-like extracellular material lined by similar cells. The extracellular material was seen densely calcified at places with cement lines and Haversian canal formation. The cells were strongly immunoreactive for epithelial membrane antigen and focally for S-100 protein and negative for glial fibrillary acidic protein.