Agminated lentiginosis: case report and review of the literature.

Agminated lentiginosis (AL) is characterized by numerous lentigines confined to a body segment, with a sharp demarcation at the midline. So far, only 13 cases have been reported in the literature. We report a 30-year-old woman with a multifocal AL. The cutaneous lesions first appeared at 5 years of age and gradually increased in number with time. Clinically, they appeared as numerous brown macules, ranging in size from 1 to 5 mm in diameter, in a peppered distribution over an area extending bilaterally on the neck, chin, and cheeks. On the trunk the lesions were localized to the left shoulder and breast, involving the axilla and upper part of the abdomen down to the umbilicus. Four café au lait macules ranging in diameter from 10 to 15 mm were present, with no evidence of neurofibromas. Histopathology of a macule showed the features of lentigo; in addition, groupings of melanocytes were observed at the dermoepidermal junction. The differential diagnosis of AL includes speckled lentiginous nevus and segmental neurofibromatosis.