Granuloma annulare (GA) is characterized by palisading granuloma, which is histopathologically distinguished by histiocytes arrayed in a palisade configuration encircling insoluble entities associated with degenerated collagen fibrils. The present case demonstrated multiple cutaneous papules showing palisading granuloma in a patient with SLE. A 39-year-old woman has been taking oral prednisolone daily, hydroxychloroquine sulfate, and belimumab for systemic lupus erythematosus (SLE). A few papules appeared on the lateral side of the left arm and gradually increased around both sides. Physical examination found multiple firm skin-colored papules ranging in diameter from 2 to 3 mm on both forearms. Some of the papules had umbilicated tops. Histopathological examination showed degenerated collagen fibers with mucin deposition surrounded by histiocyte infiltrates in the dermis. These findings are characteristic of palisading granuloma. There are several GA variants, such as generalized, subcutaneous, and perforating GA. We considered several possibilities of the mechanisms underlying characteristic histological changes; atypical generalized GA variants, dermatofibroma, and granuloma associated with cutaneous vasculitis. We made the final diagnosis of papular umbilicated GA in the context of SLE.
Keywords: cutaneous vasculitis; granuloma annulare; histopathology (hp); palisading granulomas; systemic lupus erythematosus.
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