A rare case of breast cancer in a transgender woman
A 70-year-old transgender woman presented to an institution with breast asymmetry and right-sided nipple inversion. Her past medical history was relevant for breast cancer in her maternal grandmother diagnosed in her late 60s, maternal and paternal Ashkenazi Jewish descent, and 2 years of treatment with cross-sex hormone (CSH) therapy for gender dysphoria. At the age of 68, she began CSH therapy with estradiol and monitored her breast development with serial photographs. She noticed breast asymmetry and mild right-sided nipple inversion in these photographs, which prompted her to seek medical attention. Physical examination revealed a non-tender, mobile, palpable retro areolar mass. The left breast and bilateral axillae were clinically unremarkable. The review of systems was negative for night sweats, weight loss, nipple discharge, and pain.

Imaging findings and diagnosis
Diagnostic mammography demonstrated extremely dense parenchyma and a 1.8 cm spiculated mass in her right retro areolar area with associated nipple inversion and overlying skin retraction. No axillary adenopathy was present sonographically. Directed ultrasound confirmed a 1.8 cm spiculated, non-parallel, hypoechoic mass at the retro areolar 3 o'clock radian, 1.5 cm from the nipple. The mass was biopsied under ultrasound guidance. Biopsy pathology reported concordant strongly ER/PR+ and HER2- invasive ductal carcinoma. She was referred to the multidisciplinary breast clinic for subsequent evaluation and treatment. She discontinued CSH therapy and began neoadjuvant tamoxifen 20 mg qd. She underwent bilateral mastectomies with immediate expander reconstruction and right sentinel lymph node sampling.

Surgical specimen pathology revealed a strongly ER/PR+ and HER2- grade 3 tumor measuring 1.8 cm with lymphovascular invasion. No treatment effect was observed in the tumor. Her Oncotype DX score was 28 and the tumor Ki-67 proliferation index was 37%. She declined recommended adjuvant chemotherapy with docetaxel and cyclophosphamide but elected to undergo adjuvant radiation therapy. Subsequent genetic testing was positive for BRCA2 mutation.

She plans for gender-affirming vaginal reconstruction but has encountered logistical and financial barriers. Furthermore, surgical expertise in gender-affirming vaginal reconstruction is not currently available in this region.