LOWER LIP MELANOACANTHOMA MICROSCOPICALLY PRESENTING PLASMA CELL CHEILITIS–LIKE FEATURES

Abstract

Oral melanoacanthoma is an uncommon benign pigmented lesion, microscopically presenting hyperplasia of spinous keratinocytes and dendritic melanocytes. Its pathogenesis remains uncertain, although the clinical behavior suggests a reactive origin. Oral melanoacanthoma affects mainly young adults and Blacks, with a strong female predilection. The most common oral sites are the buccal mucosa, lip, palate, and gingiva. Plasma cell cheilitis (PCC) is an inflammatory disorder of unknown etiology that affects the lips. The clinical presentation of PCC is variable, sometimes simulating malignancy, and microscopically characterized by a dense plasma cell infiltrate. Here, we present a 59-year-old Black male patient presenting blackish-colored lesions, associated with a reddish erosive area, on the lower lip, 1.5 years ago. Microscopy revealed melanoacanthoma associated with intense lymphoplasmacytic infiltrate, such as observed in PCC. If the current case represents a microscopic spectrum of melanoacanthoma or simultaneous presence of melanoacanthoma and PCC remains open to debate, however, we favor the former.