hemangiopericytoma
Pronunciation: heh-MAN-jee-oh-pair-ih-sy-TOH-mah
Vascular tumor of the central nervous system arising from pericytes around capillaries, now classified as solitary fibrous tumor.
Full Definition
Hemangiopericytoma is a rare vascular neoplasm of the CNS that arises from pericytes surrounding capillaries and small vessels. Historically considered a distinct entity, it is now classified under the broader category of solitary fibrous tumor in the current WHO classification. These tumors typically present as well-circumscribed, dural-based masses that can mimic meningiomas clinically and radiologically. Histologically, they show a characteristic 'staghorn' vascular pattern with closely packed cells around branching vessels. Unlike meningiomas, they lack epithelial membrane antigen expression and show positive staining for CD34 and STAT6. They have a higher tendency for local recurrence and distant metastasis compared to meningiomas.
Usage
Usage note: Current WHO classification prefers 'solitary fibrous tumor'; mention higher recurrence potential.
In Context
- "The tumor's staghorn vascular pattern and CD34 positivity supported a diagnosis of hemangiopericytoma." — Histopathology differential diagnosis
- "Unlike meningioma, the hemangiopericytoma showed strong STAT6 nuclear staining." — Immunohistochemical analysis