Cytological characteristics of Müllerian adenosarcoma of the uterine corpus: a case report and literature review.

Müllerian adenosarcoma of the uterus is a rare morphological variant of uterine sarcoma. Müllerian adenosarcoma has been described histologically, though it is rare in the cytological literature. This report describes the cytological findings of a case of adenosarcoma arising from the endometrium. The patient was a Japanese woman in her 40s. Endometrial cytological and histological findings were observed for 5 years, from the appearance of a polypoid lesion until adenosarcoma was suspected, and then hysterectomy was performed. Based on these longitudinal cytological and histological observations, it was possible to identify the cytological characteristics of adenosarcoma: decrease in the glandular-to-stromal ratio; increase in stromal cell density; and progression of stromal cell atypia. This case stresses the importance and usefulness of endometrial cytology in the identification of the sarcomatous component in adenosarcoma.