[Paraneoplastic skin diseases].

Various specific skin alterations can occur in patients with malignant diseases. If these skin diseases occur as associated symptoms of a malignant process, they are called paraneoplastic. In this overview, obligate and frequent facultative paraneoplastic skin diseases are assigned according to the triggering type of malignancy. Some of the processes predominantly show a link with malignant diseases of the digestive tract, e.g. acanthosis nigricans, florid cutaneous papillomatosis, necrolytic migratory erythema, Leser-Trélat syndrome, palmoplantar keratoderma, panniculitis and pityriasis rubra pilaris. Others are predominantly associated with a hematolymphoid malignoma, e.g. acquired ichthyosis, exfoliative erythroderma, necrobiotic xanthogranuloma, paraneoplastic pemphigus, plane xanthoma, pyoderma gangrenosum, scleromyxedema, Sweet syndrome and leukocytoclastic vasculitis. In a third group paraneoplastic skin diseases are pooled in association with other malignancies, e.g. Trousseau's syndrome, dermatomyositis, erythema gyratum repens, hypertrichosis lanuginosa acquisita and papuloerythroderma of Ofuji. In order to initiate targeted diagnostics for detection of an underlying malignant disease, it is essential that accomplished physicians recognize the skin diseases that represent obligate or potential paraneoplasms as such.