Benign cutaneous Degos' disease: a case report with emphasis on histopathology as papules chronologically evolve.

The following case report details a 53-year-old man with a 6-year history of the benign cutaneous or skin-limited form of Degos' disease. Clinically, the patient demonstrated a diffuse eruption of papules on the upper trunk and arms. Many papules demonstrated the classic porcelain-white centers characteristic of Degos' disease, but others exhibited different clinical morphologies that corresponded to the evolutionary stages of papules originally described by Degos. Over the course of several clinic visits, the patient underwent a total of 5 punch biopsies, the histologies of which were correlated with their clinical morphologies. Early papules were skin-colored and demonstrated a superficial and deep perivascular, periadnexal, and perineural chronic inflammatory cell infiltrate associated with interstitial mucin deposition. The overlying epidermis showed a mild vacuolar interface reaction and the histologic appearances at this early stage resembled tumid lupus erythematosus. Fully developed papules were raised with umbilicated porcelain-white centers and a surrounding erythematous rim. Histologically these exhibited a prominent interface reaction with squamatization of the dermo-epidermal junction, melanin incontinence, epidermal atrophy, and a developing zone of papillary dermal sclerosis that resembled the early stages of lichen sclerosus et atrophicus in miniature. These interface reactions were invariably confined to the central portion of the punch biopsy specimen, corresponding to the central porcelain-white area seen clinically. Additional features of fully developed papules included a prominent lymphocytic vasculitis affecting venules, a mild periadnexal infiltrate of neutrophils and/or eosinophils, and interstitial mucin deposition. In late-stage papules, the porcelain-white areas were better developed and the lesion flattened. Histologically, the degree of inflammation was generally sparse and the overall picture mirrored the classic histologic description of Degos' disease with a central roughly wedge-shaped zone of sclerosis surmounted by an atrophic epidermis and hyperkeratotic compact stratum corneum. These late-stage papules closely resembled a miniaturized version of fully developed lichen sclerosus et atrophicus confined to the center of the punch biopsy specimen.