Morcellation and the Incidence of Occult Uterine Malignancy: A Dual-Institution Review

Abstract

ObjectivesTo determine the incidence of unsuspected uterine sarcoma (UtSarc), other uterine malignancies, and potential malignancies at the time of hysterectomy or myomectomy using power morcellation.MethodsWe performed a retrospective cohort study of all women undergoing myomectomy or hysterectomy using power morcellation at 2 institutions between January 1, 2004, and May 31, 2015. The primary outcome was the incidence of uterine malignancy (UM). The predefined secondary outcome was the occurrence of other conditions associated with malignant behavior. For analysis, any UtSarc or endometrial cancer was categorized as a “uterine malignancy,” whereas other pathologies with cytologic atypia were categorized as “uterine premalignant disease” (UPM). All other pathological results were classified as “nonmalignant.”ResultsA total of 1004 women underwent hysterectomy or myomectomy using power morcellation during the studied period. Two women (1/502; 95% confidence interval [CI], 1/4144-1/139) were found to have UM pathology, 2 endometrial carcinomas and none with UtSarc (97.5% CI, 0-1/273). Six (1/167; 95% CI, 1/455-1/77) women were found to have UPM on final pathology: 2 atypical leiomyomas, 1 STUMP (smooth muscle tumors of uncertain malignant potential), and 3 endometrial atypical hyperplasias. Women with UM had uteri that weighed more than those with NM pathology (840 g vs 217.7 g, P = 0.028), and this trend was also seen with UM and UPM (435.0 g vs 217.2 g, P = 0.081). Women with UM and UPM were more likely to have a preoperative surgical indication of “uterine leiomyoma” compared with other benign etiologies (P < 0.001).ConclusionsAmong this cohort, all cases of unsuspected UM at the time of myomectomy or hysterectomy using power morcellation were found to be endometrial carcinoma. Unsuspected UM pathology had an incidence of 1 of 502. Factors associated with increased likelihood of UM or UPM were greater uterine weight and leiomyoma as the surgical indication.