Metastatic Smooth Muscle Tumor of Uncertain Malignant Potential after Laparoscopic Presuming Myomectomy

Imaging characteristics of uterine smooth muscle tumors of uncertain malignant potential: a case report and literature review

Uterine smooth muscle tumors of uncertain malignant potential (STUMPs) are rare tumors of the uterine myometrium that are often misdiagnosed, owing to limited knowledge of their characteristics on ultrasonography (US) and magnetic resonance imaging (MRI). We report a woman in her mid-30s who was hospitalized because of a pelvic tumor. A 6-cm mass was found in her lower left abdomen. US and MRI revealed a well-demarcated mass in the left adnexal area, with both cystic and solid elements, visible blood flow within the septa, a strong signal across >50% of the volume on T2-weighted imaging (T2WI), and a strong signal on diffusion-weighted imaging (DWI). After hysterectomy and bilateral salpingectomy, immunohistochemical examination confirmed STUMP. A review of the literature revealed characteristic imaging features of STUMP. Ultrasonography reveals STUMP as a solitary, well-circumscribed lesion with isoechoic or mixed echogenicity, the absence of posterior shadowing, and variations in blood flow. STUMP is characterized by strong signal intensity on T2WI, small areas of strong signal on T1WI, and non-enhancing cystic areas on contrast-enhanced MRI scans. Early diagnosis is crucial for the management and treatment of STUMP, and here we have summarized the imaging features of the lesion, thereby providing a valuable diagnostic reference.

A Transanal Endoscopic Ultrasound-guided Fine-needle Aspiration Biopsy for an Intrapelvic Tumor Diagnosed as Recurrence of a Smooth Muscle Tumor of Uncertain Malignant Potential Following Uterine Morcellation

A transoral endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) is a well-established tissue-sampling method. However, performing a transanal EUS-FNAB remains challenging. Uterine morcellation has emerged as a minimally invasive approach for benign tumor treatment. However, uterine myomas are heterogeneous and include malignant and indeterminate malignant cells. We herein report a rare case of intrapelvic tumor diagnosed by a transanal EUS-FNAB as a recurrence of smooth muscle tumors of uncertain malignant potential following uterine morcellation. Physicians should be aware that a previous uterine myoma resected under morcellation has the possibility of intra-abdominal recurrence. A transanal EUS-FNAB is a practical option for making a pathological diagnosis.