Phyllodes tumor of the vulva: Report of a rare case and review of the literature.

Phyllodes tumor occurring in the vulva is extremely rare; only 6 cases have been previously reported in the literature. The histogenetic origin of this tumor is controversial as it is being debated whether such lesions evolve from ectopic breast tissue, cutaneous apocrine glands, and most recently, anogenital mammary-like gland. We report an 18-year-old Kuwaiti girl who presented with a painless mass in the left labium majus, which was subsequently excised. Microscopic examination revealed morphologic pattern characteristic of benign phyllodes tumor. Immunostaining demonstrated the presence of estrogen receptors and progesterone receptors in the epithelial component. We present this case to emphasize the importance of recognizing this uncommon lesion occurring at an extremely unusual site. We also discuss the histogenesis of phyllodes tumor and related lesions occurring in the anogenital region in light of the current literature along with a brief review of the previously reported cases of vulvar phyllodes tumor.