[Detecting skin cancer: paraneoplastic skin diseases].

Skin diseases represent the second most common paraneoplastic manifestations after endocrine disorders. Paraneoplastic dermatoses may arise as the first clinical sign of occult malignancies, or manifest during the course of a previously diagnosed neoplasm. Dermatoses belonging to the group of obligate paraneoplastic syndromes manifest only in the presence of underlying malignancies. Other skin diseases may be associated with malignancy in a subset of patients.