Benign cephalic histiocytosis: a case report and review.

Benign cephalic histiocytosis is a rare non-Langerhans histiocytosis characterized by a self-healing eruption of papules and macules on the head and neck that occurs during infancy or childhood. Histologic and ultrastructural evaluations show a dermal proliferation of histiocytes with intracytoplasmic comma-shaped bodies, coated vesicles, and desmosome-like structures with an absence of Birbeck granules. We report a case of benign cephalic histiocytosis in a 9-month-old boy who presented with tan papules on his face that spread to his lower extremity and subsequently began to regress at 30 months of age. We review the features of this rare entity through a literature review and discuss the differential diagnosis.