Signs and Symptoms of Congenital Nevus
While congenital nevi are typically larger than common acquired nevi, they cannot always be distinguished by size alone. They often are round or oval, clearly demarcated, and sometimes slightly elevated. Pigmentation usually is even, although some congenital nevi have a speckled appearance. Coarse, dark, hairs may be present, and the surface sometimes has a pebbled texture.
Large congenital nevi, particularly those overlying the head, neck, or spine, has been associated with melanocyte proliferation in the soft tissues surrounding the brain and spinal cord. This may be of clinical importance, as it can give rise to excessive fluid accumulation around the brain, seizures, or melanoma. The incidence of this melanocyte proliferation is not known, as it is not always symptomatic.
Congenital nevi typically grow in proportion to the developing child, although rapid periods of enlargement can be seen.