Case report: Identification of endometrial adenosarcoma on conventional Papanicolaou smear

Adenosarcoma is a distinctive biphasic tumor of low malignant potential that accounts for 1-2% of uterine sarcomas. It usually presents as a large mass that protrudes into the cervical canal. Due to its rarity, cytopathologists may overlook it on Papanicolaou (Pap) smear. Here, we report a case presenting with enlarged vaginal mass. She was treated with surgical excision. There was recurrence after three months. Pap smear showed atypical stromal cells. However, they were not detected by cytopathologists the first time. We provide a brief summary of the cellular features of stromal cells and suggest immunocytochemistry with cell transfer smear for differential diagnosis of adenosarcoma on Pap smear.