Cutaneous neuropathology: neurofibromas, schwannomas and other neural neoplasms with cutaneous and extracutaneous expressions.

Major syndromes in which cutaneous and extracutaneous nervous neoplasms are frequently associated include: 1) dysgenetic syndromes or phacomatoses (tuberous sclerosis and neurofibromatosis), 2) multiple schwannoma syndromes (schwannomatosis and Carney's complex), 3) multiple mucosal neuromas syndrome, 4) neurocutaneous pigmentary syndromes (Peutz-Jeghers-Touraine syndrome and neurocutaneous melanosis), and 5) sundry associations (cutaneous meningiomas and cutaneous metastases of neuroblastoma or carcinoid tumors). The early clinical and pathological recognition of these cutaneous neural and pigmentary associated lesions should stimulate the search for centrally located neural or neuroendocrine neoplasms, some of which might be life-threatening.