++
SUMMARY
Congenital melanocytic nevi are nevomelanocytic proliferations that develop during embryogenesis and present at or shortly after birth.
Patients with large (>20 cm) congenital melanocytic nevi and multiple lesions are at increased risk for central nervous system complications and cutaneous melanoma.
Although current management is supportive—consisting of regular examinations, symptomatic treatment, and, possibly, surgical removal—promising future treatments, including targeted therapies, may improve quality of life for these patients.
++
DON’T FORGET
++
CLINICAL PEARLS
Sequential examination can help differentiate banal changes from those associated with malignancy.
Although surgical removal may theoretically lower cutaneous melanoma risk, there is no conclusive evidence supporting this; therefore, discussions about removal should include a thorough discussion of the risks and benefits of intervention.
++
PATIENT EDUCATION POINTS
++
Congenital melanocytic nevi (CMN) are nevomelanocytic proliferations that develop during embryogenesis. Although most CMN are apparent at birth, some may not become clinically apparent for months or years after birth and are termed tardive CMN. The most common presentation of CMN is in the form of an isolated small nevus measuring less than 1.5 cm in greatest diameter. Less common is the presence of isolated CMN measuring between 1.5 and 20 cm. Rarely, CMN can be large, measuring over 20 to 60 cm in diameter, or they can present as multiple isolated CMN. Although most CMN do not adversely affect health, some can be aesthetically or symptomatically distressing, can cause functional impairment, or can be accompanied by extracutaneous anomalies, which most commonly involve the central nervous system (CNS). Additionally, patients with CMN have an increased risk for melanoma development in CMN or within the CNS. An improved understanding of CMN, its pathogenesis, and its risk stratification has helped shape current management recommendations.
++
Generally, the incidence of CMN decreases as its diameter increases.1-3 Small CMN, which are commonly less than 1.5 cm, are found on 1% to 2% of infants. Large CMN, which are at least 20 cm, are estimated to be found in 1 of 20,000 infants.4
++
Although CMN occur in all races and sexes, some studies have suggested there may be a slight increase in incidence among infants of African descent4 and in female infants.5-7
++
Melanocytes arise from neural crest cells. Once formed along the mediodorsal aspect of the closing neural tube, neural crest cells migrate to the skin via dorsal and ventral pathways, to the uveal tract of the eye, and to the leptomeninges.8 While prevailing understanding of CMN ...