Uterine smooth muscle tumors with uncertain malignant potential: analysis following fertility-saving procedures

The aim of this study was to analyze the clinical and reproductive outcomes of patients treated with myomectomy who were histologically diagnosed with uterine smooth muscle tumor of uncertain malignant potential (STUMP).

Patients who were diagnosed with STUMP and underwent a myomectomy at our institution between October 2003 and October 2019 were identified. Variables of interest obtained from the institution's database included patient age, relevant medical history, pre-operative appearance of the tumor on ultrasound, parameters of the surgical procedure, histopathological analysis of the tumor, post-operative clinical course, and course of follow-up, including reinterventions and fertility outcomes.

There were a total of 46 patients that fulfilled the criteria of STUMP. The median patient age was 36 years (range, 18-48 years) and the mean follow-up was 47.6 months (range, 7-149 months). Thirty-four patients underwent primary laparoscopic procedures. Power morcellation was used for specimen extraction in 19 cases (55.9% of laparoscopic procedures). Endobag retrieval was used in nine patients and six procedures were converted to an open approach due to the suspicious peri-operative appearance of the tumor. Five patients underwent elective laparotomy due to the size and/or number of tumors; three patients had vaginal myomectomy; two patients had the tumor removed during planned cesarean section; and two underwent hysteroscopic resection.There were 13 reinterventions (five myomectomies and eight hysterectomies) with benign histology in 11 cases and STUMP histology in two cases (4.3% of all patients). We did not observe any recurrence as leiomyosarcoma or other uterine malignancy. We did not observe any deaths related to the diagnosis. Twenty-two pregnancies were recorded among 17 women, which resulted in 18 uncomplicated deliveries (17 by cesarean section and one vaginal), two missed abortions, and two pregnancy terminations.

Our study found that uterus-saving procedures and fertility-preservation strategies in women with STUMP are feasible, safe, and seem to be associated with a low risk of malignant recurrence, even while maintaining the mini-invasive laparoscopic approach.