Keratoacanthoma centrifugum marginatum—A rare variant of keratoacanthoma: Case report and literature review

Keratoacanthoma centrifugum marginatum (KCM) is a rare variant of keratoacanthoma and is characterized by progressive peripheral growth with accompanying central healing. Here, we report a case of multiple KCM. A 53-year-old man presented with multiple erythematous papulonodules on both upper limbs and neck for >2 years. His skin lesions enlarged in an annular manner with central residual cribriform scarring that eventually formed confluent plaques (2–8 cm in diameter) with elevated hyperkeratotic borders. Skin biopsy of a developed matured nodule on the right forearm was consistent with that of classical keratoacanthoma. KCM was diagnosed on the basis of clinical and pathological presentation. Low-dose acitretin (0.7 mg/kg/day) was administered and the skin lesions improved significantly within 3 months after the treatment. In this case, we present the clinical and histological features of KCM and discuss the different effective treatment modalities.