The management of congenital melanocytic nevi

Proliferative Nodule in Small Congenital Melanocytic Naevus After Childhood

“…Some authors insist that the risk is related to lesion size (6), while other investigators disagree (4). The excision of small and medium-sized CMNs when feasible is advised by many authors (7,8), although not all (1,5). Melanomas arising from small and medium-sized CMNs are apt to occur after puberty, to be located at the margin of the naevi, and to be exclusively of epidermal origin (4).…”

Congenital melanocytic nevi: Clinical and histopathologic features, risk of melanoma, and clinical management

“…19 Several histologic patterns in giant congenital melanocytic nevi have been identified, including those of a compound or dermal nevus, neural nevus, blue nevus, and spindle and epithelioid cell nevus. 16,20 In the neural nevus type, the melanocytic elements may take on the histologic appearance of a neurofibroma. The nevomelanocytes show neuroid differentiation manifest as spindled wavy nuclei with tapered ends embedded in a delicate fibrous stroma and forming nevic structures that resemble neuroid tubes and Meissner corpuscles.…”

“…Such a pattern occasionally is associated with congenital bone abnormalities such as clubfoot and spina bifida. 20 In the blue nevus type, the melanocytic elements may acquire the appearance of common blue nevus, cellular blue nevus, or giant blue nevus. 12 In rare cases, giant congenital blue nevi of the scalp invade the dura and the brain.…”

“…21,22 In the spindle and epithelioid cell nevus type, the deep reticular dermis is infiltrated by epithelioid and spindle cells often mixed with small banal nevomelanocytes or neuroid elements (combined nevus). 12,20 Small congenital melanocytic nevi may show junctional, compound, or dermal nevus patterns, and some can be histologically indistinguishable from common acquired melanocytic nevi. 17,23,24 Studies of congenital melanocytic nevi in infants have shown that the pattern of distribution of nevomelanocytes and the depth of the melanocytic proliferation are established very early in life.…”

“…These associations include scoliosis, spina bifida, atrophy, asymmetry, clubfoot, elephantiasis, and cranial bone hypertrophy. 1,11,12,20 Another important association is neurocutaneous melanosis, a rare congenital disorder characterized by the presence of giant or multiple melanocytic nevi associated with benign or malignant melanotic tumors of the central nervous system. This latter phenomenon is also known as leptomeningeal melanocytosis.…”