Endolymphatic stromal myosis of the uterus. Clinicopathological analysis of five cases.

Five cases of endolymphatic stromal myosis (ELSM) were studied using histological, histochemical and immunohistochemical methods. ELSM is a well-differentiated tumor resembling the normal endometrial stoma, with a low mitotic activity. So ELSM is considered as a kind of potentially malignant tumor different from endometrial stomal sarcoma and benign stromal nodules as well, though it can metastasize to the outside of uterus. ELSM may be derived from the stem cells that are normally present in the stroma of uterus, and can manifest multidifferentiation.