Intravascular leiomyomatosis with uterine lipoleiomyoma.

A very rare case of uterine lipoleiomyomata with intravascular leiomyoma in a 48-year-old woman is described. Located in the corpus of the uterus, the lipoleiomyomata showed proliferation of leiomyocytes intermingling with mature adipocytes. Intravascular leiomyoma was present in the broad ligament. It exhibited only spindle cells, and was reactive for HHF35 actin, without adipocytes. No continuity was detected between these tumors. Immunohistochemical studies revealed that the same portion of the intravascular leiomyoma was positive for S-100 alpha protein, NSE, factor VIII-related antigen, and HHF35 actin. These findings suggest that the leiomyomatous tumor components arise from multipotent undifferentiated mesenchymal stem cells.