Multiple clear-cell acanthoma (Degos): histochemical and ultrastructural study of two cases

Two patients with clear-cell acanthoma with multiple lesions are reported; histologic and histochemical findings are similar to previous descriptions. The ultrastructural study confirms the overload of glycogen in keratinocytes, associated with an increase of mitochondria and nuclear deformations. The abundance of Langerhans' cells is emphasized. Extrusion of glycogen by keratinocytes and its phagocytosis by Langerhans' cells is suggested.