Introduction

Uterine smooth muscle tumours are primarily classified as benign leiomyomas or malignant leiomyosarcomas, with diagnosis based on cytologic atypia, mitotic activity, and tumour cell necrosis. Smooth muscle tumour of uncertain malignant potential (STUMP), a rare variant accounting for 2–5% of myomas, cannot be unequivocally classified as benign or malignant and most commonly affects women aged 45–55. The clinical presentation is similar to that of fibroids, and management is surgical, though standardized procedures are lacking due to the uncertain malignant potential. While prognosis is generally favourable, STUMP may recur, occasionally as leiomyosarcoma, highlighting the need for careful postoperative follow-up.

Material and methods

This retrospective study included 12 patients with histopathologically confirmed STUMP treated between 2019 and 2024. Clinical data were analysed, and patients were followed until July 2025 to assess survival, recurrence, and outcomes.

Results

Twelve patients with histopathologically confirmed STUMP were analysed, with a median age of 44.5 years and a median tumour size of 6.25 cm. Most patients presented with heavy menstrual bleeding (50%) or a pelvic mass (42%). Surgical treatment included hysterectomy in 50% of cases and myomectomy in 42%, performed via laparotomy, laparoscopy, or transvaginal approaches. After a median follow-up of 44 months, no recurrences were observed.

Conclusions

Smooth muscle tumour of uncertain malignant potential remains a rare uterine neoplasm of uncertain malignant potential, requiring postoperative histopathological confirmation, individualized management, and long-term surveillance due to its risk of recurrence or metastasis.