Lipomatous angiomyofibroblastoma of the vulva: A case report and review of the literature.

Lipomatous angiomyofibroblastoma is extremely rare, with only 16 cases reported to date. We herein describe an additional case arising in the left vulvar region of a 49-year-old woman. The resected 5.3-cm yellowish tumor predominantly consisted of fat cells (85% of the tumor), together with medium- and small-sized vessels, multifocal fibrotic areas and pseudoangiomatous spaces. Spindle, rounded, and/or epithelioid tumor cells proliferated in a nest and/or cord-like pattern, or singly within perivascular fibrous tissues and between fat cells. The tumor cells were positive for vimentin, estrogen receptor, progesterone receptor, B-cell lymphoma 2, and CD10, but were negative for desmin, cytokeratin, epithelial membrane antigen, S-100 protein, human melanoma black 45, C-kit and p40. Ultrastructural examination revealed that these tumor cells exhibited fibroblastic characteristics. Lipomatous angiomyofibroblastoma should be discriminated from other lipomatous tumors, including spindle cell lipoma, angiomyolipoma and cellular angiofibroma containing numerous fat cells.