Multicentric retroperitoneal leiomyosarcoma with satellite lesions not found on PET-CT: A case report and literature review

Most retroperitoneal leiomyosarcomas are clinically silent and are usually detected late, so a large size main tumor accompanied by satellite lesions might be presented. We report a case of a large multicentric retroperitoneal leiomyosarcoma with satellite lesions in the left iliac region, mimicking an abscess, was found on pre-operative pelvic computed tomography (CT). Positron emission tomography (PET-CT) was performed, but revealed only focal bony destruction of the left ilium and no discernable lesions in the abdomen. After resection of the iliacus satellite lesion, CT and magnetic resonance imaging (MRI) of the abdomen revealed another huge retroperitoneal leiomyosarcoma with invasion of the left kidney and ureter, descending colon and left iliac arteries. The patient was then treated with a multidisciplinary extensive excision operation. The clinical presentation, operative findings and imaging findings were reported and related articles were reviewed.