Angiomyofibroblastoma of the vulva diagnosed preoperatively: A case report.

A 50-year-old woman (gravida 2, para 2) first noticed a small nodule in the right labium majus 2 years prior to the initial visit to the Hachinohe Red Cross Hospital (Hachinohe, Japan), which had gradually increased in size. On physical examination, a well-circumscribed, elastic, firm, goose egg-sized, subcutaneous mass protruding from the right labium majus was identified. On magnetic resonance imaging (MRI), the lesion was hypointense on T1-weighted images and was well-circumscribed, strongly enhanced and homogeneous on gadolinium-enhanced images, measuring 7.5×4 cm. The same tumor had measured 2.6 cm on an MRI performed 6 years earlier. Based on the clinical course and imaging findings, angiomyofibroblastoma was diagnosed and surgical resection of the tumor was performed. The tumor was well-circumscribed and highly vascular. The intraoperative blood loss was 70 ml. Histopathologically, the tumor cells were concentrated around blood vessels, were spindle-shaped to oval with mild atypia, and were positive for vimentin, desmin, neural cell adhesion molecule (N-CAM), CD-34, estrogen receptor and progesterone receptor, and negative for S-100. Based on these findings, the diagnosis of angiomyofibroblastoma was confirmed. Angiomyofibroblastoma is a benign mesenchymal tumor that occurs in the female external genitalia. Differentiation of this tumor from aggressive angiomyxoma, a fast-growing infiltrative malignancy that occurs in the same region, may be challenging. The diagnosis of angiomyofibroblastoma is usually based on the histopathological findings of the resected specimen. The present case is of value, as the angiomyofibroblastoma was successfully diagnosed preoperatively based on the clinical course and imaging findings.