Squamous Cell Cancer – Keratoacanthoma Centrifugum Marginatum

Keratoacanthoma Centrifugum Marginatum is a very rare variant of Keratoacanthomas that I rarely encounter in my The Woodlands dermatology and Conroe dermatology offices.  Keratoacanthoma Centrifugum Marginatum begins as scaly nodule which gradually enlarges in an annular configuration by extending peripherally in all directions.  As the Keratoacanthoma expands, the center resolves with atrophy of the skin.  These Keratoacanthomas can become extremely large reaching sizes of up to 30cm.  If surgical excision cannot be performed, Methotrexate and Etretinate have been used to arrest the growth.  Unlike other Keratoacanthomas, Keratoacanthoma Centrifugum Marginatum almost never spontaneously resolves.