Current management of primary cutaneous CD30+ T-cell lymphoproliferative disorders.

Primary cutaneous CD30+ T-cell lymphoproliferative disorders (PCLPDs) are the second most common type of cutaneous T-cell lymphoma. These disorders comprise a spectrum of clinically benign lymphomatoidpapulosis (LyP) and primary cutaneous anaplastic large-cell lymphoma (ALCL). The peak incidence of LyP is in the 5th decade of life, and the incidence of primary cutaneous ALCL peaks in the 6th decade, but children are also affected. Both LyP and primary cutaneous ALCL have an excellent prognosis. However, LyP is associated with development of malignant lymphoma (mycosis fungoides, Hodgkin lymphoma, or ALCL) in 20% of cases, and also with an increased risk of non-lymphoid cancers. The diagnosis of LyP is difficult and often delayed. Primary cutaneous ALCL must be distinguished from secondary skin lesions in systemic ALCL, which confer a poor prognosis. Correlation of clinical findings with histopathology and immunopathology (stains for ALK kinase, epithelial membrane antigen, and cutaneous lymphocyte antigen) are important to achieve a correct diagnosis. When a diagnosis of CD30+ PCLPD is established, minimal clinical staging is required. Low-dose methotrexate (10-25 mg weekly) is the most effective therapy for PCLPD but is usually reserved for aggressive cases of LyP and multifocal lesions of cutaneous ALCL Many patients with LyP can be followed expectantly, with special attention to changes in character of the skin lesions or development of lymphadenopathy. Patients with localized cutaneous ALCL can be treated with irradiation. Extracutaneous spread of disease is an indication for multiagent chemotherapy. Other treatment alternatives are discussed.