Giant congenital melanocytic nevus (bathing trunk nevus) associated with lipoma and neurofibroma: report of two cases.

Giant congenital melanocytic nevi are rare and occur in about one out of every 2,00,000 to 5,00,000 births. There is a significant association between bathing trunk nevus and neurofibromatosis and lipomatosis. Apart from this, association of bathing trunk nevus with abnormalities like spina bifida occulta, meningocele, club foot and hypertrophy or atrophy of deeper structures of a limb, have been described. We are herewith reporting two cases of bathing trunk nevi. In our first case, an eight-year-old girl presented with a bathing trunk nevus studded with multiple, large nodules. Histopathological examination of the biopsy taken from one nodule revealed features of both neurofibroma and lipoma. To the best of our knowledge, features of both these hamartomas in one nodule of a single patient are probably not reported in the literature. In our second case, a 12-year-old girl presented with bathing trunk nevus and she had spina bifida occulta. She also had lipoma in the lesion of bathing trunk nevus. Both of our patients had satellite melanocytic nevi over the face, forearm, upper back and legs. Our second patient, in addition, had small melanocytic nevi over the medial canthus and sclerocorneal junction of the right eye. By the time this girl presented to us, the melanocytic nevus started fading in color and it had become brownish. We are reporting these cases for their peculiarities and for their rare features.