Giant uterine mass with uterine smooth muscle tumor of uncertain malignant potential: A case report.

Background: Uterine smooth muscle tumor of uncertain malignant potential (STUMP) is a rare tumor belonging to a group of smooth muscle tumors that possess both benign and malignant features, complicating the diagnosis.Case report.We present the case of a 41-year-old primiparous woman who complained of heavy menstrual bleeding and severe pressure symptoms in the lower abdomen for 3 months. Magnetic resonance imaging revealed a large intramural myoma measuring 35 × 25 cm in the lower uterine corpus. A laparotomy including total hysterectomy was performed. Grossly, the uterine mass measured 38.5 × 35.4 × 20.4 cm in the largest diameter and weighed 18.3 kg. Pathological analysis revealed a uterine mass diagnosed as a smooth muscle tumor of uncertain malignant potential. The patient was normally discharged 7 days after surgery and decided to follow up without further treatment. At the time of this report, the patient had been followed up as an outpatient for 18 months without recurrence.

Conclusion: Giant uterine STUMP is extremely rare and difficult to diagnose on physical examination and imaging findings alone. It is important to consider the possibility of an underlying malignancy when performing a preoperative examination and to perform frozen biopsy if malignancy is suspected. During follow-up, patients should undergo consultation with a gynecologic oncologist and should be surveilled closely because of the possibility of recurrence or metastasis.