Mosaic neurofibromatosis type 1

A 24-year-old man presented with numerous lentigines and multiple cafe-au-lait macules on both sides of the face, neck, and trunk as well as on the proximal area of the upper extremities and in the axillae. The pigmented lesions had a Blaschko-linear distribution on the upper trunk and were limited to the left side of the abdomen, with a sharp demarcation at the midline. Multiple, cutaneous neurofibromas were found on the trunk, and ophthalmologic examination showed a Lisch nodule in the left iris. The clinical findings and their widespread but segmental distribution were consistent with a diagnosis of mosaic neurofibromatosis type 1.