Background: Müllerian adenosarcoma is a rare morphologic variant of uterine sarcoma that, although well described histologically, is scarcely mentioned in the cytologic literature.
Case: A 75-year-old female was suspected of having atypical endometrial hyperplasia on an endometrial smear. However, subsequent imaging techniques revealed the presence of a bulky, polypoid mass filling the uterine cavity. On pathologic examination of the hysterectomy specimen, the polypoid tumor was diagnosed as mullerian adenosarcoma, homologous, with sarcomatous overgrowth, in which the sarcomatous component was compatible with high grade endometrial stromal sarcoma. Imprint smears of the tumor consisted of two morphologic patterns, sarcomatous and glandular. The sarcomatous tumor cells, with coarse chromatin and relatively scant cytoplasm, formed small aggregates or appeared alone. These cells were semiround or oval and had conspicuous nucleoli. In addition to these observations, small and large clusters of glandular cells with mild atypism were interspersed with the sarcomatous cells.
Conclusion: Cytologic examination of müllerian adenosarcoma well reflects its pathologic features.