Multiple keratoacanthoma centrifugum marginatum—a case report and systematic review
Keratoacanthoma centrifugum marginatum (KCM) is a rare variant of keratoacanthoma (KA). Although many cases and reviews of solitary KCM have been reported, few studies have been published on multiple KCM. This article describes a typical case of multiple KCM, and summarizes the clinical characteristics, especially the treatment and prognosis of patients with multiple KCM. We systemically searched for “keratoacanthoma centrifugum marginatum” in the MEDLINE, EMBASE, Cochrane, and SinoMed databases, without time limitation. Sixty-five KCM records were found. After the selection process, ten available articles on multiple KCM were included. We present the case of a female patient with multiple progressive lesions, which are typical of KCM, on the face, a site where few KCM lesions have been observed. Multiple KCM is more common in males; the male-to-female ratio is 7:2 based on the cases that have been reported to date. KCM occurs mostly on the limbs, but lesions on the face and buttocks have also been reported. Both oral and topical (iso)retinoid treatments for multiple KCM were shown to be effective. In patients who are unresponsive to retinoid treatment, methotrexate and prednisone can be used as second-line treatments. Multiple KCM has characteristic clinical features. Although it progresses rapidly without treatment, proper treatment, including retinoids, immunosuppressants, corticosteroids, and excisional surgery, often leads to a favorable outcome.