[Specific and nonspecific skin manifestations in leukemia]

The cutaneous manifestations of leukemias are conventionally divided into nonspecific benign lesions and specific malignant lesions. Specific lesions (leukemia cutis) are localized or disseminated infiltrations of the skin by malignant leukemic cells which may involve all layers of the skin. The clinical appearance of leukemia cutis is variable and may range from papules and nodules to a generalized cutaneous eruption and erythroderma. The histopathologic examination of the skin lesion is essential for diagnosis of leukemia cutis. Specific skin lesions are usually observed in patients with an aggressive clinical course and are associated with a poor prognosis. However, an overall survival of patients with specific skin lesions of chronic lymphocytic leukemia is significantly better, as compared with other types of leukemia. Rarely, skin lesions containing leukemic cells are present before evidence of leukemia cutis can be detected in the peripheral blood and bone marrow (aleukemic leukaemia cutis). Leukemic skin lesions should be differentiated from numerous nonspecific lesions, which may be present in up to 80% of all patients with leukemia.