Acquired (digital) fibrokeratoma.

Histologic examination of fifty cases of acquired digital fibrokeratoma discloses three histologic variants of these lesions, viz: a tumor composed of thick dense and closely packed collagen bundles, a variant with an increased number of fibroblasts in the cutis, and a type with an edematous and poorly cellular structure. The acquired digital fibrokeratoma is considered as resulting from a neoformation of collagen by the fibroblasts. The acanthosis of the epidermis is probably secondary to the dermal alteration.