<s>[INST] <<SYS>> This is a medical question of type : information <</SYS>> What is (are) Hemangiopericytoma ? [/INST] Hemangiopericytoma is a term used to described a group of tumors that are derived from pericytes, the cells normally arranged along specific types of blood vessels called capillaries and venules. These types of tumors are typically slow-growing, may be either benign (non-cancerous) or malignant (cancerous), and may occur anywhere in the body. </s>