Leukemia Cutis—The Current View on Pathogenesis, Diagnosis, and Treatment

SIMPLE SUMMARY: Leukemia cutis occurs in different types of leukemia, most commonly in chronic lymphocytic leukemia and acute myeloid leukemia. Its varied clinical appearance makes it difficult to differentiate from other skin lesions. The leukemic skin changes are localized or disseminated and can be located in any site of the body. The diagnosis is mainly based on the clinical characteristics and histopathologic, as well as immunophenotypic features of the skin lesions. The treatment of leukemia cutis depends on the specific diagnosis of hematologic malignancy and is aimed at eradicating the primary underlying disease. Local irradiation for skin lesions is sometimes useful for palliative treatment. ABSTRACT: Leukemia cutis (LC) is defined as the leukemic infiltration of the epidermis, the dermis, and the subcutaneous tissue. Leukemia cutis may follow or occur simultaneously with the diagnosis of systemic leukemia. However, cutaneous lesions are occasionally diagnosed as the primary manifestation of leukemia. Leukemic skin infiltrations demonstrate considerable variation regarding a number of changes, distribution, and morphology. The highest incidence of LC is observed in chronic lymphocytic leukemia, monocytic and myelomonocytic acute myeloid leukemia, and T-cell lineage leukemia. Although the pathogenic mechanism of the invasion of leukemic cells into the skin is not well understood, chemokine receptors and adhesion molecules as well as the genetic characteristics of leukemia are thought to play a role. Leukemic skin lesions may be localized or disseminated and may occur alone or in combination on any site of the skin, most frequently in the trunk and extremities. The most common clinical presentations of leukemia cutis are papules, nodules, macules, plaques, and ulcers. In most patients, the complete or partial resolution of cutaneous infiltrations occurs simultaneously with hematologic remission. However, in patients with resistant disease or recurrent skin infiltration, local radiotherapy can be used. This review presents recent data on the pathogenesis, diagnosis, and treatment of leukemic skin involvement in different types of leukemia.