Clinic pathological features of angiomyofibroblastoma in vulva

Objective: To analyze the clinicopathological features and differential diagnosis of angiomyofibroblastoma (AMFB) of the vulva. Methods: Two cases of AMFB were examined by light microscopy and immunohistochemical study and to discuss the clinicopathological features and differential diagnosis of AMFB with the reference to the literature. Results: Tumors were all circumscribed, and < 5 cm in diameter. Microscopically, the tumors were composed of spindle or polygonal cells that were cellularly or hypocellularly arranged with perivascular accentuation in a mucoid or fibrocollagenous background. The tumors contained numerous small-to medium-sized blood vessels, which were characteristically thin walled. Immunohistochemically, two cases of tumor cells were positive for vimentin, SMA, CD34(+) and FVIII(+). Desmin and MSA were positive in one case; Cytokeratin, S-100, CD31 were negative in both. Conclusion: AMFB is a rare, benign soft tissue tumor that occurs in the genital tract of adult women. The origin remains unclear, but it is suggested that an origin from a perivascular pluripotent stem cell that is capable of myofibroblastoma differentiation. Angiomyofibroblastoma should be differentiated from other neoplasms of the vulva such as aggressive angiomyxoma, superficial angiomyxoma and cellular angiofibroma.