Leiomyosarcoma of the inferior vena cava: a case report of a challenging diagnosis of abdominal pain.

Leiomyosarcoma of the inferior vena cava (IVC-LMS) is a rare malignant tumor, accounting for approximately 2% of all leiomyosarcomas, and predominantly affecting women over 50 years of age. Patients are often asymptomatic or present with nonspecific abdominal pain, which can hinder and delay diagnosis. We report the case of an 80-year-old male patient with a 3-month history of nonspecific abdominal pain. The diagnosis was established only intraoperatively, when the smooth muscle neoplasm initially suspected to originate from the duodenum was identified as an IVC-LMS. The patient underwent partial resection of the IVC with prosthetic interposition, followed by adjuvant chemoradiotherapy. Complete surgical resection remains the gold standard treatment of IVC-LMS and the only approach with curative potential. Prognosis largely depends on the stage at diagnosis.