Lichen planus pigmentosus inversus limited to the umbilicus — a case report with dermoscopic findings

Abstract

Lichen planus pigmentosus inversus (LPPI) is a rare variant of lichen planus. Its etiopathogenesis is not fully understood. Koebner’s phenomenon is considered to be a potential triggering factor, which may explain the localization of skin lesions in flexural and intertriginous areas that are not exposed to ultraviolet. A case of a 32-year-old female patient is reported, in whom the umbilicus was the only site involved by LPPI. Dermatoscopy revealed irregular pinkish structureless areas intermingled with whitish lines, grey dots, and a grey-black structureless area. The observed features did not allow a clear diagnosis. Due to the unknown duration of the lesions and technical difficulties with videodermoscopic monitoring, the lesion was excised with a 1-mm margin. Histopathological examination was consistent with the diagnosis of LPPI.