This 25-year-old Asian man presented with numerous warty papules and plaques involving his upper back, neck, and upper chest. He had no prior family or personal history. Confluent and reticulated papillomatosis of Gougerot and Carteaud is an unusual condition, resembling acanthosis nigricans but with a more central distribution. The etiology is unclear, but some authors have implicated Pityrosporum and metabolic disturbances, while other patients clearly show a familial component. With our patient, the etiology appears idiopathic. The histology in this case is typical, but it is nonspecific, as the acanthosis, papillomatosis, and hyperkeratosis can be seen in seborrheic keratoses, acanthosis nigricans, epidermal nevi, and others. Occasionally, Pityrosporum organisms are seen. Clinicopathologic correlation is required.
Histologic sections of skin show epidermal acanthosis, papillomatosis, hyperkeratosis with mild basilar keratinocytic hyperpigmentation.