keratoacanthoma /ker′ətō·ak′anthō″mə/ [Gk, keras + akantha, thorn + oma, tumor] , a benign, rapidly growing, flesh-colored papule or nodule of the skin with a central plug of keratin. The lesion is most common on the face or the back of the hands and arms. It disappears spontaneously in 4 to 6 months, leaving a slightly depressed scar. Biopsy is often necessary to differentiate it from a squamous cell carcinoma.
