Neurofibromatosis

Neurofibromatosis (commonly abbreviated NF) is a genetically-inherited disorder in which the nerve tissue grows tumors (i.e., neurofibromas) that may be harmless or may cause serious damage by compressing nerves and other tissues. The disorder affects all neural crest cells (Schwann cells, melanocytes, endoneurial fibroblasts). Cellular elements from these cell types proliferate excessively throughout the body forming tumors and the melanocytes function abnormally resulting in disordered skin pigmentation.The tumors may cause bumps under the skin, colored spots, skeletal problems, pressure on spinal nerve roots, and other neurological problems.

Acoustic neuroma

An acoustic neuroma, correctly called a vestibular schwannoma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve (CN VIII).