Classification of Primary Cutaneous Lymphomas

摘要

Cutaneous lymphomas represent clonal proliferations of neoplastic T or B lymphocytes. They have been recognized as a heterogeneous group with distinct variability in clinical presentation, histopathology, imrnunophenotyping and prognosis. After the primary gastrointestinal lymphomas cutaneous lymphomas represent the second most common group of extranodal lymphomas, with an estimated annual incidence of 0.5-1/100,000.Primary cutaneous lymphomas often show a completely different clinical behavior and prognosis compared to histologically similar systemic lymphomas that may involve the skin secondarily. Therefore, primary cutaneous lymphomas require different types of treatment. For this reason, a new consensus classification based on both, the European Organization for Research and Treatment of Cancer (EORTC) classification for primary cutaneous lymphomas and the World Health Organization (WHO) classification for tumors of hematopoietic and lymphoid tissues as the first common classification, namely the WHO-EORTC classification, has been established. In the following review we will give an overview of the most frequent cutaneous T cell lymphomas (CTCL): mycosis fungoides (Mf), Sezary syndrome (SS), anaplas-tic large cell lymphoma and lymphomatoid papulosis (LyP), and of the most frequent cutaneous B cell lymphomas (CBCL): cutaneous follicle center lymphoma, marginal zone lymphoma and diffuse large cell lymphoma, which represent nearly 90% of all cutaneous lymphomas. Rare entities occurring primarily in the skin are included in table 1.