In the brain, hemangioblastomas occur not only in the cerebellum but elsewhere in the cranium. The endolymphatic sac tumor of the inner ear is now recognized as a cause of hearing loss and this region is now routinely evaluated in all VHL patients. Growth rates in VHL are comparable to those seen in sporadic cases of pheochromocytoma. Pheochromocytomas can occur in ectopic sites and imaging should encompass the most common areas of concern. Renal lesions in VHL exhibit a pattern of growth and regression.
Cysts tend to stay constant, slowly enlarge or regress whereas solid tumors grow slowly.
Hundreds of tny islets of renal tumor can be found in microscopic preparations of VHL kidneys. Solid tumors should be removed when they reach 2.5-3 cm in diameter and surgery is greatly aided by intraoperative ultrasound. MRI is useful in patients with compromised renal function but CT is the best overall modality for screening and following patients with renal disease. Although cystic disease of the pancreas is benign it can be symptomatic. Obstruction of the bowel or biliary tree as well as pancreatic insufficiency can be seen.