Pulmonary and intra-abdominal spread of benign metastasizing leiomyoma: a radiologic review

Background. Benign metastasizing leiomyoma (BML) is a rare entity characterized by the extrauterine spread of benign smooth muscle tumors, most commonly to the lungs and peritoneal cavity, often occurring years after hysterectomy for uterine leiomyomas. Its pathogenesis remains unclear, and distinguishing it from malignant counterparts is critical for appropriate management. Case presentation. We report the case of a 62-year-old female, status post-total hysterectomy 15 years ago for uterine leiomyomas, who presented with progressive abdominal distension, intermittent dry cough, and exertional dyspnea over six months. Physical examination revealed mild abdominal distension without palpable masses, and respiratory findings were unremarkable. Laboratory investigations, including tumor markers, were within normal limits. Contrast-enhanced computed tomography (CECT) of the chest, abdomen, and pelvis demonstrated multiple well-circumscribed soft tissue lesions in the abdomen and pelvis, along with bilateral pulmonary nodules. A CT-guided biopsy of the pulmonary lesions revealed smooth muscle proliferation with low mitotic activity, and immunohistochemical analysis confirmed estrogen and progesterone receptor positivity, supporting the diagnosis of BML. Conclusion. This case highlights the rare post-hysterectomy recurrence of benign diffuse leiomyomatosis with pulmonary and peritoneal metastases, emphasizing the role of imaging and histopathology in diagnosis. Awareness of this entity is crucial to avoid misdiagnosis as malignancy, ensuring appropriate management and follow-up.