Pericyte formation occur in -: (A) Kaposi sarcoma, (B) Glomus tumor, (C) Hemangiopericytoma, (D) Myopericytoma
Answer is C. Haemangiopericytoma is an uncommon tumor arising frompericytes. Pericytes are cells present external to the endothelialcells of capillaries and venules. This is a rare tumorthat can occur at any site and at any age and may vary insize from 1 to 8 cm.Microscopically, the tumor is composed of capillariessurrounded by spindle-shaped pericytes outside thevascular basement membrane forming whorledarrangement. These tumor cells may have a high mitoticrate and areas of necrosis. Silver impregnation stain (i.e.reticulin stain) is employed to confirm the presence ofpericytes outside the basement membrane of capillariesand to distinguish it from haemangioendothelioma Ref: Harsh Mohan - Textbook of Pathology, 6th Edition.page no.414