ABSTRACT
In respect to the concept of nosologic entities as defined by recent lymphoma classifications the diagnostic evaluation of primary cutaneous lymphomas includes the integration of clinical, morphological, phenotypic, and molecular characteristics. Several studies have demonstrated that the diagnostic accuracy employing clinical and histological features alone ranges from 50% to 75%, but reaches 80% when morphologic features are combined with the immunophenotypic or genotypic characterization of tumor cells (1). Immunohistochemical (IHC) identification of the tumor cell phenotype plays such a crucial and invaluable role in the diagnostic work-up of cutaneous lymphoma (CL) that it can be regarded as a mandatory step in establishing the correct diagnosis (2).Moreover, several forms of CL such as cytotoxic lymphomas can only be correctly identified by phenotyping. On the other hand, identical phenotypes and cytomorphologic changes can be seen in clinically and prognostically different CL. Thus, the final diagnosis has always to be based on integrative synopsis of all clinical, histopathological, IHC, and molecular biological findings.
