Unexpected uterine smooth muscle tumor of uncertain malignant potential and sarcoma: A single center cohort study in South Korea

Abstract

Objective: To evaluate the risk of encountering unexpected uterine smooth muscle tumors of uncertain malignant potential (STUMPs) or sarcomas during surgical treatment of mesenchymal tumors of the uterus using morcellation. Material and methods: Data were collected retrospectively from subjects who were pathologically diagnosed with uterine leiomyoma or its variants, STUMP or other premalignant mesenchymal tumors of uterus, or sarcoma during surgical treatment between July 2014 and June 2017. Results: A total of 3785 women were investigated; 2824 laparoscopic procedures (74.6%) were performed, and an electronic power morcellator was used in 1636 patients (43.2%). Sixteen women (0.42%) were diagnosed with STUMP and 14 (0.37%) were diagnosed with uterine sarcoma. The incidence rate of unexpected STUMP or uterine sarcoma was 0.61% (23 of 3785 women); unexpected STUMP in 13 (0.34%), and unexpected sarcoma was in 10 (0.26%). Moreover, the unexpected leiomyosarcoma rate was 0.08% (3 in 3785). The rate of unintended morcellation of STUMPs was relatively high at 0.26% (10 in 3785), however, that for uterine sarcomas was 0.05% (2 in 3785). Conclusion: The risks of unintended morcellation were very low for sarcomas and STUMPs, although the risk of the latter was approximately 5-fold that of the former. To reduce the unintended dissemination of tumors, patients suspected of having malignancies should be provided adequate information regarding their treatment options as well as their associated risks. Meanwhile, improved preoperative screening methods for STUMP and sarcoma should be established. Keywords: Endometrial stromal sarcoma, Leiomyosarcoma, Mesenchymal tumor of uterus, STUMP, Uterine sarcoma