Effects of Morcellation of Uterine Smooth Muscle Tumor of Uncertain Malignant Potential and Endometrial Stromal Sarcoma: Case Series and Recommendations for Clinical Practice

Study Objective To assess the consequences of inadvertent morcellation of uterine smooth muscle tumors of uncertain malignant potential (STUMPs) or endometrial stromal sarcomas (ESSs) and to investigate the findings of surgical re-exploration procedures including the frequency and nature of disease dissemination. Design A retrospective chart review from January 1, 1999, to October 31, 2014. Cases were identified by cross-referencing the terms “morcellate” and “morcellation” with the terms “smooth muscle tumor of uncertain malignant potential,” “STUMP,” “endometrial stromal sarcoma,” and “low grade endometrial stromal sarcoma” within the University of Michigan electronic medical record. One additional patient was identified at St. Joseph Mercy Hospital using the pathology database with keywords “uterine sarcoma” (Canadian Task Force classification III). Setting University of Michigan, Ann Arbor, MI, and St. Joseph Mercy Hospital, Ann Arbor, MI. Patients Patients who underwent hysterectomy or myomectomy with morcellation and were subsequently found to have a STUMP or ESS on pathologic review. Interventions None, retrospective chart review. Measurements and Main Results Eight patients were identified who underwent morcellation and were subsequently found to have a STUMP or ESS. Five patients underwent power morcellation, 2 patients underwent hand morcellation, and 1 patient underwent laparoscopic bivalving. Seven patients had a secondary surgical assessment 6 to 19.2 weeks after their initial procedure. Five patients were found to have benign implants comprised of myometrium or endometrium, 1 patient had widespread malignant implants, and 1 patient had no evidence of peritoneal implants. One patient underwent power morcellation within a specimen bag after supracervical hysterectomy. This patient had evidence of benign implants at the time of her re-exploration procedure. All patients who underwent surgical re-exploration are living. The patient with malignant implants has been maintained on megestrol for more than 8 years without disease recurrence. The remaining patients have no evidence of disease with follow-up ranging from 2.8 to 35.1 months. Conclusion Surgical re-exploration procedures after morcellation of a uterine STUMP or ESS have a high likelihood of detecting peritoneal implants, which can be benign or malignant.