Retroperitoneal oncocytoma: case report and review of the imaging features.

Oncocytomas are uncommon tumours that occur in a number of specific anatomical locations within the head, neck, chest, abdomen and pelvis. When occurring in the retroperitoneum, oncocytomas almost always arise from either the kidney or adrenal gland. With this case we present the imaging findings of an exceptionally rare retroperitoneal oncocytoma whose site of origin is neither the kidney nor adrenal gland.

Assessment of tumor invasion of the vena caval wall in renal cell carcinoma cases by magnetic resonance imaging.

PURPOSE: We evaluated the role of magnetic resonance imaging (MRI) in patients with renal cancer and inferior vena caval involvement with reference to its ability to characterize the extent and nature of inferior vena caval tumor extension and wall invasion. MATERIALS AND METHODS: The study included 12 consecutive patients with renal cancer and inferior vena caval involvement. All patients underwent imaging on a 1.5 Tesla MRI unit. Coronal, axial T1 and axial T2-weighted images were performed in all cases, while in 6 3-dimensional gadolinium enhanced magnetic resonance angiography and venography were also performed. Images were assessed for the extent and nature of tumor extension, that is tumor versus thrombus, and invasion of the inferior vena caval wall. Imaging results were compared with operative findings. RESULTS: On MRI the extent and nature of the inferior vena caval tumor was correctly defined in all cases. The sensitivity, specificity and accuracy of inferior vena caval wall invasion were 100%, 89% and 92%, respectively. CONCLUSIONS: In patients with renal cancer and inferior vena caval involvement MRI defines the tumor level in the inferior vena cava. It is also a sensitive technique for detecting vessel wall invasion and provides important preoperative information for surgical planning.