[Multiple infundibuloma].

A 42-year-old man presented with multiple hypopigmented macules, 4 to 10 mm wide, irregularly shaped and symmetrically distributed on the neck and face, with a 10 years duration. Histological examinations showed a plate-like epithelial proliferation below the epidermis. The cells had a pale cytoplasm, with few PAS positive granules. In the lower part of the proliferation the peripheral cells were palisading and surrounded by a dense elastic network. Serial sections showed connections with the normal outer root sheath of the neighbour follicles, and with the epidermis. This pattern is very characteristic of Mehregan's tumor of follicular infundibulum. Four distinctive presentations of this tumor can be observed, in spite of its rarity: multiple macules of the upper chest or face (4 cases have previously been described), tumors of follicular infundibulum occurring in Cowden's disease or in the natural course of organoid nevi, and the most common solitary form of the face. With their striking clinical features, the eruptive or multiple forms of this tumor should be recognized as a distinctive clinical entity. Possible transformation into basal cell carcinoma has been described in one of these cases, and long time supervision should be recommended.