Penile Fibroadenoma Arising From Anogenital Mammary-Like Glands in a Transgender Woman

Anogenital mammary-like glands (AGMLG) are specialized glands of the anogenital region capable of giving rise to lesions analogous to those of the breast. Fibroadenomas arising from AGMLG are well documented in the vulva but are exceedingly rare in male genital anatomy. We report a penile fibroadenoma arising from AGMLG in a 29-year-old transgender woman with a progressively enlarging mass while receiving feminizing hormone therapy. Histologic examination demonstrated a well-circumscribed fibroepithelial lesion with intracanalicular architecture, ductal structures with a bilayered epithelium, and paucicellular stroma without atypia. Immunohistochemistry supported mammary-type differentiation. This case highlights the importance of recognizing AGMLG-derived lesions and their morphologic overlap with breast counterparts.