Neurofibromatosis is characterized by dysplasia, hyperplasia, and tumor formation of ectodermal nerve tissue. NFⅠ neurofibromas commonly occur in the distal peripheral nerves, spinal nerve roots, especially the cauda equina. Cranial nerves are most commonly affected in the auditory, optic, and trigeminal nerves. Intramedullary tumors include ependymomas and astrocytomas, with hemispheric gliomas being the most common intracranial tumors. The tumors vary in size and are arranged in a spindle cell pattern, with nuclei resembling a picket fence. Cutaneous or subcutaneous neurofibromas are mostly located in the dermis or subcutaneous tissue and lack a cell membrane. The skin pigment spots are caused by the deposition of melanin in the basal cells of the epidermis. NFⅡ is characterized by bilateral vestibular schwannomas and multiple meningiomas, with loosely arranged tumor cells often containing giant cells.