Uterine smooth muscle tumors of uncertain malignant potential (STUMP): pathology, follow-up and recurrence

The term smooth uterine muscle of uncertain malignant potential (STUMPs) indicates a group of uterine smooth muscle tumors (SMTs) that cannot be diagnosed unequivocally as benign or malignant. Diagnosis, surgical management, and follow-up of this neoplasm remain controversial, especially in pre-menopausal women with fertility desire, due to the non aggressive behaviour and prolonged survival rate when compared to leiomyosarcomas. However, recurrence is estimated between 8.7% and 11% and may include delayed-recurrences. We reported five cases of uterine masses treated by surgical procedure diagnosed as STUMP on final pathology. Four patients underwent a total abdominal hysterectomy with or without salpingo-oophorectomy. One patient underwent excision of uterine mass and subsequent total abdominal hysterectomy plus bilateral salpingo-oophorectomy after the diagnosis of STUMP. All patients in our study remained recurrence-free to date (with a follow up period ranging from 6 to 81 months). Based on our experience and in consideration of the lack of consensus regarding the malignant potential, diagnostic criteria, gold-standard treatment and follow-up, we believe that close multidisciplinary management is mandatory in the event of STUMP. We suggest that gynaecologist, dedicated pathologist (with high level of expertize in gynaecological pathology) and oncologist should work as a team in the counselling and management of this neoplasm from detection till completion of follow up. Furthermore, we recommend immunohistochemistry to investigate the overexpression of p16 and p53 in order to identify the cohort of patients at increased risk of recurrence who may benefit from more aggressive surgical-oncological strategies.