Endolymphatic stromal myosis: unique presentation and ultrastructural study.

We describe a case of endolymphatic stromal myosis (ESM) in which the lesion presented uniquely as recurrent frond-like cervical polyps. The lesion behaved aggressively, spreading to the peritoneum. Ultrastructurally, this tumor closely resembled proliferative phase endometrial stroma, in accord with the theory that ESM is a low-grade stromal sarcoma. The ultrastructural correlations may aid in developing future therapy, including progestagen administration for these unusual tumors.