Rare skin (nevi) and meningeal pigmentation with a
high risk of cutaneous or neural malignant degeneration.
Only a few cases have been described since 1987.
Probably a developmental problem in the neural
crest cells that ultimately form the skin and meninges.
At birth, large pigmented nevi, usually on the trunk,
buttocks, or perineum. Cerebral MRI should be done before age 4 months to
detect central nervous system (CNS) involvement.
Large pigmented nevi, usually on the trunk,
buttocks, or perineum. CNS function may be normal at birth, but MRI
examination is necessary to exclude brain or spinal cord involvement. If the
CNS is involved, thickening and pigmentation of the meninges with focal
accumulation of melanotic cells or brainstem lesions is observed.
Progressive pigmentation and thickening of the meninges lead to cerebral
deterioration, increased intracranial pressure, mental retardation,
seizures, hydrocephalus, cranial nerve palsies, and spinal cord compression.
CNS involvement (especially presence
of increased intracranial pressure, brainstem lesions) should be excluded by
MRI and/or eye fundus examination. If neuraxial blockade is foreseen for
postoperative pain management, spinal cord involvement should be excluded.
In case of excision surgery, large blood loss should be foreseen.
In the presence of hydrocephalus, usual
precautions to prevent any increase in intracranial pressure must be
provided. If a spinal or epidural block is performed, the needle should not
be inserted through a pigmented lesion to avoid skin coring and possible
perimedullar implantation of melanocytes.
As for any neonatal anesthesia. Patients may
require repeated general anesthesia or deep sedation for dressing changes.
Patients with seizure activity should have medication optimized prior to
surgery or receive intraoperative intravenous supplementation.
Giant Neonatal Nevus with No CNS Involvement: Sporadic;
seems to be more frequent in Asian populations; early excision or laser
therapy is performed by many medicosurgical teams for fear of malignant transformation.
Cruz MA, Cho ES, Schwartz RA, et al: Congenital neurocutaneous melanosis.