Large polypoid angiomyofibroblastoma of the vulva: report of a case

Abstract

We report a case of angiomyofibroblastoma which arose in the vulva of a 46-year-old woman. The tumor formed a large pedunculated polypoid mass, measuring 14 cm in maximal dimension, which hung down from the right labium majus. It consisted of a dense or loose proliferation of fibroblastic and myofibroblastic cells on an edematous background, and the tumor cells occasionally exhibited an increased cellularity around well-developed, medium-sized or small blood vessels. In small areas, conglomerates of capillaries exhibited an appearance resembling that of capillary hemangioma. Tumor cells were immunoreactive for vimentin, desmin, estrogen receptor, and progesterone receptor, but not for α-smooth muscle actin, CD34, CD10, S-100 protein, calretinin, podoplanin, or cytokeratin. Angiomyofibroblastoma usually appears as a small subcutaneous nodule, and the formation of a large pedunculated polypoid mass is rare. The differential diagnosis from aggressive angiomyxoma and other mesenchymal tumors which preferentially involve the vulvo-vaginal region was briefly discussed.

Keywords: Angiomyofibroblastoma; polypoid lesion; vulva.

Figure 1

A: A large polypoid tumor hung down from the right labium majus. B: T1-weighted MRI with contrast enhancement demonstrated a large, well-circumscribed subcutaneous tumor showing an intense and irregular enhancement. C: The tumor was composed of alternating hypercellular and hypocellular areas and consisted of a proliferation of spindle cells on the edematous and highly vascularized stroma. (Hematoxylin-eosin stain, × 10). D: Plump spindle cells surrounded small vessels and occasionally formed small cellular trabeculae or cords. (Hematoxylin-eosin stain, × 25). E: Some blood vessels showed hyalinized thickening of the walls and intramural chronic inflammatory cell infiltration. (Hematoxylin-eosin stain, × 25). F: In small areas, capillary-sized anastomosing blood vessels formed dense aggregates resembling capillary hemangioma. (Hematoxylin-eosin stain, × 25). G: The cytoplasm of some tumor cells was immunoreactive for desmin (× 100). H: The nuclei of most tumor cells were immunoreactive for estrogen receptor (× 25).