title: [Clinicopathologic characteristics of myopericytoma].
abstract: OBJECTIVE
  To investigate the clinicopathologic characteristics and differential diagnosis of myopericytoma.
  
  
  METHODS
  Six cases of myopericytomas were analyzed by light microscopy and immunohistochemistry (LSAB detection method).
  
  
  RESULTS
  Tumors from 3 females and 3 males were found on the extremities and chest wall. The ages of these 6 patients ranged from 16 to 58 years. Histologically, all tumors were unencapsulated. The neoplastic cells were oval to spindle shaped with eosinophilic cytoplasm, had a myoid appearance and showd areas of concentric perivascular proliferation around lesional blood vessels which were present with focal myxoid stroma. Morphologically in some cases the tumor overlap myofibroma, hemangiopericytoma or glomus tumor. One tumor was located entirely within the lumen of a vein. In another case, the tumor displayed cellular pleomorphism, mitotic activity, necrosis should be diagnosed as malignant myopericytoma. The neoplastic cells were positive for SMA and negative for CD31, CD34, S-100, and CK.
  
  
  CONCLUSIONS
  Myopericytoma is composed of oval to spindle shaped myoid cells with a striking tendeny for concentric perivascular growth. These cells differentiate towards perivascular myoid cells or myopericytes. Extremely rare malignant myopericytoma exist.
authors.affiliation: Department of Pathology, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China.
authors.forename: Yan-bo
authors.initials: YB
authors.lastname: Zhu
authors.forename: Qing
authors.initials: Q
authors.lastname: Wei
authors.forename: Fei
authors.initials: F
authors.lastname: Yuan
authors.forename: Xiao-long
authors.initials: XL
authors.lastname: Jin
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D005918:Glomus Tumor / Q000378:metabolism / Q000473:pathology; D006393:Hemangiopericytoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D047708:Myofibroma / Q000378:metabolism / Q000473:pathology; D009383:Neoplasms, Vascular Tissue / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D014746:Vimentin; C498862:Acta2 protein, rat