RADIOLOGY: MUSCULOSKELETAL: Case# 32917: NEUROFIBROMATOSIS-1, RENAL AND PELVIC MASSES. Patient is a 44-year-old female s/p partial resection of a brain tumor. The examination is being requested to rule out abdominal and pelvic metastases. Gas is seen within the urinary bladder which is otherwise unremarkable. Bilateral symmetrical excretion of contrast is seen in the kidneys, without evidence for hydronephrosis. There are innumerable small subcapsular nodules in the kidneys bilaterally. A large 12 cm x 12 cm heterogeneously enhancing mass is seen in the lower pelvis with destruction of the inferior sacrum and posterior most aspect of the right iliac bone. Other small nodules are seen in the retroperitoneum and the paraspinous region of the lower spine.