Clinical resolution of a neonatally eroded giant congenital melanocytic nevus.

We report an unusual occurrence of spontaneous pigmentary regression with a desmoplastic reaction in a neonatally eroded giant congenital melanocytic nevus. This process has been documented with photographs and skin biopsy specimens. Neonatal histology demonstrated connective tissue proliferation. Histology at age 5 years also demonstrated a very high proportion of amelanotic dermal nevus cells. Regression of pigmentation in our patient may be due to a decrease in melanin production by dermal nevus cells rather than a decrease in their number.