[Skin diseases as indicators of cancer].

In contrast to the obligatory paraneoplasias, which are usually rare, diseases such as Sweet's syndrome, thrombophlebitis or herpes zoster are more common. But they are less frequently associated with neoplasia. The risk of overlooking an associated neoplasm is therefore greater. In this article, prototypic diseases are presented with their clinical appearance, possible pathogenesis and treatment options; this is accompanied by raising awareness of potential associations with cancer. The emphasis on the distinct features of the neoplasm-associated forms should enable more reliable detection of these variants and hopefully contribute to an earlier diagnosis of associated neoplasms. These peculiarities include the jumping or wandering thrombophlebitis occurring as Trousseau's syndrome, recurrent, severe courses with involvement of the oral mucosa in Sweet's syndrome or the necrotizing, gangrenous clinical course, often with a multisegment distribution pattern of herpes zoster. Studies on the association of facultative cutaneous paraneoplasias with certain tumors are presented. However, no general recommendation for tumor screening in patients with herpes zoster, Sweet's syndrome or thrombophlebitis can be given. In atypical courses, particularly severe manifestations or the absence of other causes, more extensive diagnostic procedures appear appropriate in order not to miss possibly associated neoplasms.