Unveiling the intermediate tumour: a case report of uterine smooth muscle tumour of uncertain malignant potential and review of magnetic resonance imaging features.

Abstract

Uterine smooth muscle tumour of uncertain malignant potential (STUMP) is a rare and diagnostically challenging entity, lying on the spectrum between benign leiomyomas and malignant leiomyosarcomas. Its unpredictable biological behaviour and potential for metastasis and progression to leiomyosarcoma necessitate surgical removal and long-term surveillance for late recurrence and malignant transformation. We present a case of uterine STUMP in a 49-year-old woman with a large uterine mass exhibiting suspicious magnetic resonance imaging (MRI) features preoperatively. She underwent a hysterectomy with histological confirmation of STUMP. Through radiologic-pathologic correlation, we highlight key MRI features that can suggest the diagnosis of STUMP and aid in differentiating it from benign leiomyomas. While differentiating STUMP from leiomyosarcoma on imaging remains challenging due to its rarity and overlapping imaging characteristics, imaging plays a crucial role in detecting complications and guiding follow-up. Multidisciplinary management in tertiary centres with gynaecologic oncology expertise is essential for comprehensive patient care.