Clinical history: A 61 year old female presented with a large, soft mass of the vulva. Excisional biopsy performed.
What is the most probable diagnosis?
Angiomyofibroblastoma is a benign neoplasm that arises mainly in the vulvovaginal region of women of reproductive age. Grossly, the tumors are usually less than 5 cm in diameter and well-circumscribed. The cut surface is tan to white with a rubbery consistency.
Microscopically, the tumor is well delineated from the surrounding tissues but is not encapsulated. It is composed of ovoid to spindled cells that cluster around the numerous blood vessels generating hyper- and hypo-cellular areas. The tumor cells may be multinucleated. Mitotic figures are rarely identified.
The primary differential diagnosis for the angiomyofibroblastoma is a deep (aggressive) angiomyxoma. The deep angiomyxoma is infiltrative and demonstrates homogenous cellularity in contrast to the variable cellular density seen in the angiomyofibroblastoma. Additionally, the angiomyxoma has medium to large sized vessels in contrast to the small to medium sized vessels of the angiomyofibroblastoma.
The tumors are generally cured by resection with clear margins. Only rarely does the tumor undergo sarcomatous transformation