Suprarenal retroperitoneal liposarcoma with intracaval tumor thrombus: an imaging mimic of adrenocortical carcinoma.

We report a 57-year-old previously healthy man who presented with dull right upper quadrant pain, weight loss, fatigue, and night sweats. Computed tomography demonstrated a large, heterogeneously enhancing, soft tissue mass with no macroscopic fat above the right kidney with tumor thrombus extending into the inferior vena cava and right atrium. Positron Emission Tomography scanning demonstrated intense Fluorodeoxyglucose avidity in the primary tumor and tumor thrombus. The presumptive radiological diagnosis was adrenocortical carcinoma, but surgical pathology revealed a dedifferentiated liposarcoma. We conclude that suprarenal retroperitoneal liposarcoma should be included in the differential diagnosis for an apparent adrenal mass with venous invasion.