title: Hemangiopericytoma. An ultrastructural study.
mesh_terms: D002648:Child; D006393:Hemangiopericytoma / Q000473:pathology*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009298:Nasal Polyps / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D009666:Nose / Q000473:pathology; D009669:Nose Neoplasms / Q000473:pathology*