Solitary fibrous tumor/hemangiopericytoma of the optic canal.

Solitary fibrous tumor/hemangiopericytoma seldom arises from the optic nerve sheath. Herein, we describe the clinical, radiological, and histological findings of a solitary fibrous tumor/hemangiopericytoma arising from the optic nerve sheath and occupying the optic canal. The diagnosis is challenging both clinically and histologically as it clinically simulates a commoner lesion, i.e., an optic nerve sheath meningioma, and histological features can be mistaken for a fibroblastic/transitional meningioma. Differentiating these lesions from meningioma is crucial both for therapeutic and prognostic reasons. Moreover, hemangiopericytoma with high-grade features arising within the brain is known to develop extracranial metastases, and hence warrants a close follow-up.