Lichen Sclerosus and Keloidal Morphea Overlap

Lichen sclerosus (LS) and morphea are chronic inflammatory sclerosing dermatoses that occasionally exhibit overlap. While their coexistence within the same lesion is increasingly recognized, nodular presentations remain exceptionally rare. We report a 50-year-old woman with a strikingly distinctive presentation of a solitary, well-circumscribed, exophytic nodule on the left posterior thigh, characterized by an ivory-colored peripheral rim, and an erythematous central zone. Histopathological examination revealed features of both lichen sclerosus (epidermal atrophy, basal vacuolar alteration, and homogenized upper dermal collagen with a subjacent band-like lymphocytic infiltrate) and keloidal morphea (deep dermal sclerosis with keloidal collagen fibers extending into subcutaneous septa, entrapped adnexal structures, and lymphoplasmacytic infiltrate). The exophytic nodular morphology with keloidal features expands the known clinical spectrum of LS-morphea overlap. Recognition of this unusual variant may prevent diagnostic confusion with other nodular dermal proliferations.

Abstract from PubMed