Vulvar angiomyofibroblastoma misdiagnosed as subcutaneous lipoma: a case report and literature review.

BACKGROUND: Angiomyofibroblastoma (AMFB) of the vulva is a rare benign mesenchymal tumor of the vulva that affects the vulva and vagina of adult women. Often mimicked by other vulvar masses such as vestibular macrocystic glands, subcutaneous lipomas, and dermoid cysts, AMFB can be detected by histopathology. Here, we present a case where AMFB was initially misdiagnosed as a subcutaneous lipoma. By highlighting the role of preoperative pathology and imaging in the diagnostic and treatment process, we aim to improve AMFB recognition and better management.

CASE SUMMARY: A 59-year-old woman, postmenopausal for 10 years, reported that she first saw a vulvar mass 14 years ago, and it has gradually grown since then. A color Doppler ultrasound at another hospital detected a slightly hyperechoic mass in the fat of the left perineum measuring 7.2 × 3.0 × 4.5 cm, 36 mm from the body surface. The lesion was well circumscribed but internally heterogeneous; no intralesional blood flow was detected. No preoperative biopsy was obtained. The lesion was excised surgically. Intraoperatively, the surgeons identified a cystic mass on the lateral side of the left labium majus, measuring approximately 7.0 × 4.0 × 4.0 cm, soft, irregularly shaped, encapsulated, and clearly distinguished from adjacent tissues. Histopathological examination of the resection specimen from the left labia majora confirmed angiomyofibroblastoma. At the 3-month follow-up, no tumor recurrence was observed.

CONCLUSION: This case confirmed that AMFB is prone to misdiagnosis. Before the operation, imaging examinations should be combined, and surgical resection should be performed after a confirmed diagnosis based on pathological and immunohistochemical examinations.