BACKGROUND: Glassy cell carcinoma of the endometrium is an extremely rare variant of adenosquamous carcinoma, and it has a poor prognosis. In postmenopausal women it typically presents as unprovoked, painless uterine bleeding. Tissue sampling is necessary to establish the diagnosis.
CASE REPORT: A 58-year-old postmenopausal woman on no hormone replacement therapy experienced 2 months of intermittent uterine bleeding. An office transvaginal ultrasound discovered a 1.7-cm intracavitary leiomyoma, but because the endometrial stripe was not visualized, an endometrial biopsy was performed. She was found to have a Stage 1 A endometrial poorly-differentiated adenosquamous carcinoma, glassy cell carcinoma tumor of 1.5 cm in greatest dimension. She underwent a robotic total hysterectomy, bilateral salpingo-oophorectomy, pelvic lymph node mapping, and bilateral pelvic lymphadenectomy.
CONCLUSIONS: Glassy cell carcinoma of the endometrium can present as an intracavitary leiomyoma in postmenopausal women.

Keywords: Carcinoma, Adenosquamous, Endometrial Neoplasms, Leiomyoma