ENDOMETRIAL STROMAL SARCOMA WITH FOCAL SMOOTH-MUSCLE DIFFERENTIATION - RECURRENCE AFTER 17 YEARS - A FOLLOW-UP REPORT WITH DISCUSSION OF THE NOMENCLATURE

In 1977, a case report was published describing a 28-year-old woman wi th an endometrial stromal tumor that showed foci of myogenic different iation. The term ''stromomyoma'' was introduced to encompass both this type of neoplasm as well as ''uterine neoplasms resembling ovarian se x-cord tumors'' (UTROSCTs). More than 17 years later, the tumor recurr ed, involving the right ovary, sigmoid colon, small bowel, abdominal w all, and omentum, The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed, Applying the recent classification and diagnostic criteria of endometr ial mesenchymal neoplasms, we have concluded that this tumor was a low -grade endometrial stromal sarcoma (LGSS). The formerly proposed term ''stromomyoma'' implies a benign tumor, in contrast to the obviously m alignant nature of this particular tumor. Focal myogenic differentiati on of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarc omas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.