Adenopathy and an extensive skin patch overlying a plasmacytoma (AESOP) syndrome, first described 16 years ago, is characterized by a slowly expanding red or brown patch (classic variant) or plaque (morphea-like variant) overlying a solitary plasmacytoma of the bone. Early recognition can be life-saving, as it is an early presentation of polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome, which may be fatal. There are two forms: the classic variant, which presents as a smooth, shiny macule with abnormal visibility of skin vessels, and the morphea-like variant, which presents as a plaque where the skin is folded, giving a "peau d'orange" appearance. The locations are frequently above the rib cage, above the sternum, or the scalp. Seventy-five percent of the patients develop regional lymphadenopathy within a few months. Histopathologic study reveals a capillary proliferation in the dermis. The diagnosis relies on subsequent identification of the plasmacytoma. At the time of a presumptive diagnosis, only 40% of patients have fulfilled the diagnostic criteria of POEMS. Treatment depends on the final hematologic diagnosis, but radiation of the plasmacytoma is required.