Summary
Keratoacanthoma (KA) is a common benign epithelial tumor of pilosebaceous origin. The tumors are composed of keratinizing squamous cells. The disease is characterized by rapid evolution and, most often, by spontaneous resolution. Two familial forms of multiple KA's have been described. Ferguson Smith multiple KA and Muir-Torre syndrome. Multiple KA's of Ferguson Smith type is a very rare disorder that is inherited in an autosomal dominant manner. The responsible gene has been mapped to chromosome 9q22-q31. Muir-Torre syndrome involves multiple sebaceous tumors (for example, hyperplasia, adenoma, epithelioma and carcinoma) or KA occurring together with several visceral carcinomas. KA's usually begin in childhood, adolescence, or in early adult life. Several of them appear suddenly, mostly on the head, slowly involute, and periodically reappear for years. The diagnosis is based on history and physical examination and it is confirmed by histological examination. Although KA's usually involute spontaneously, treatment hastens resolution and provides improved cosmetic result. All therapeutic modalities for solitary KA are applicable also for multiple KA's. Systemic approaches such as retinoids, methotrexate, 5-Fluoro-Uracil or interferon alfa-2a have been shown to be effective and promising for the management of multiple KA's.*Authors: Dr AC. Katoulis and Dr E. Bozi (August 2005)*.
