Recognizing an IVC leiomyosarcoma: CT imaging hallmarks and the utility of 3D rendering.

Inferior vena cava (IVC) leiomyosarcoma is a rare and aggressive malignancy arising from smooth muscle cells of the IVC wall, accounting for less than 1 in 100,000 adult malignancies. It carries a poor prognosis, with high recurrence rates and 5-year disease-free survival reported as low as 6%. Clinical presentation is often vague, including abdominal or back pain, lower extremity edema, and weight loss, making imaging pivotal for diagnosis. Contrast-enhanced CT (CECT) is the modality of choice, but diagnosis remains challenging due to overlap with more common pathologies such as renal cell carcinoma, hepatocellular carcinoma, adrenal tumors, and retroperitoneal lymphadenopathy. This pictorial review presents a curated series of cases highlighting the spectrum of imaging appearances of IVC leiomyosarcoma. By showcasing both typical and atypical imaging patterns, this review aims to broaden radiologists' diagnostic awareness and improve confidence in identifying this elusive tumor. Special emphasis is placed on 3D CT imaging techniques, including optimal acquisition protocols and post-processing methods, to enhance lesion visualization and vascular mapping. Early and accurate recognition is crucial, as aggressive surgical resection remains the mainstay of treatment. Understanding key imaging clues can facilitate timely diagnosis and intervention, ultimately impacting patient outcomes in this rare but life-threatening disease.