Cutaneous paraneoplasia.

Paraneoplasias are frequently the first sign of a subjacent malignant tumor. Although relatively rare, they need to be recognized by dermatologists to make an early diagnosis and improve the prognosis related especially to the neoplasia. This contribution presents the morphologic aspects and the differential diagnosis of the main paraneoplasias, which include acanthosis nigricans, tripe palms, Leser-Trélat sign, acquired ichthyosis, acquired hypertrichosis lanuginosa, pityriasis rotunda, erythema gyratum repens, palmo-plantar keratoderma, Bazex syndrome, and dermatomyositis, hoping to contribute to the familiarity of dermatologists with the identification and early diagnosis of this group.