Histiocytoma Cutis: A Variant of Xanthoma

Dermatologists are generally agreed that there exists a cutaneous entity which has been variously known as fibroma simplex (Unna, 1896), nodulus cutaneus (Arning and Lewandowsky, 1911), dermatofibroma lenticulare (Schreus, 1930), histiocytoma cutis (Woringer, 1931, and Senear and Caro, 1936), dermatofibroma (Traub and Monash, 1932) and nodular subepidermal fibrosis (Michelson, 1933). The appearance of the firm, pink to tan, slightly elevated, usually single, slowly growing nodules is characteristic and is familiar enough to require no elaboration here; the histologic features with ordinary stains are likewise relatively constant (with occasional exceptions), easily recognized and well known. A recent review by Sweitzer and Winer1summarized all this material concisely and well. There are, however, two unsolved problems in connection with this lesion. The first is its seeming rarity in some parts of the country. One of us (H. L. A.) encountered but 1 recognized instance of it during more than three years