“The Uncertain and Unpredictable”: Uterine Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP)—Three Cases

Abstract

Smooth muscle tumors of uncertain malignant potential (STUMP) are rare tumors, which cannot be unequivocally diagnosed as benign or malignant and carry recurrence risk of 8.7–11% including delayed recurrence. The literature on STUMP is scarce and consensus regarding gold standard treatment and follow-up is lacking. The aim of this study was to identify the patients diagnosed as STUMP at VPS Lakeshore Hospital and Research Centre and to study the patient characteristics and outcome. All patients who underwent hysterectomy from 2012 January to 2016 December were identified, among which three patients were diagnosed as STUMP in the final histopathology report. Case files and reports were reviewed. Patient characteristics and follow-up data were analyzed. Two patients underwent open abdominal hysterectomy. One underwent total laparoscopic hysterectomy. All three patients were premenopausal. Two patients presented with menorrhagia and one patient with irregular cycles. One patient had undergone modified radical mastectomy for carcinoma breast and was on tamoxifen. One patient succumbed to death due to recurrence within 1 year of surgery, and two patients are asymptomatic and on follow-up (follow-up period 3 and 2 years). Difficulties in diagnosis of STUMP, unpredictability of recurrence and literature review are discussed. Patients with diagnosis of STUMP should be informed regarding risk of recurrence including delayed recurrence. The patients require closer and long-term follow-up.