Hemangiopericytoma of the uterus vs. hemangiopericytoma-like endometrial stromal sarcoma: a histopathological approach to differential diagnosis.

A case of uterine hemangiopericytoma is reported and compared to a case of endometrial stromal sarcoma of low-grade malignancy (also termed endolymphatic stromal myosis). Their clinical features are quite similar, whereas their morphological appearances are fairly unalike. The actual existence of the uterine hemangiopericytoma is emphasized, although the very nature of this tumour is still disputed by some authors. Light-microscopy findings supplemented by special stains allow a definite diagnosis even without ultrastructural study. Histological criteria for differentiating hemangiopericytoma of the uterus from uterine mesenchymal neoplasms with a pericytomatous-like pattern are discussed.