Von Hippel-Lindau syndrome (VHL) is an autosomal dominant genetic disorder characterized by the abnormal growth of blood vessels in certain parts of the body (angiomatosis). Very small blood vessels (capillaries) "knot" together to form benign growths known as angiomas or hemangioblastomas. These may develop in the retinas of the eyes (retinal hemangioblastomas) or in the brain or spinal cord, or in the inner ear (endolymphatic sac tumors). Vascular tumors may also occur in the kidneys (renal cell carcinoma), pancreas (cysts, microcystic cystadenomas, or pancreatic neuroendocrine tumors) and/or adrenal glands (pheochromocytoma). The symptoms of VHL vary greatly and depend on the size and location of the growths.