Cutaneous CD30-positive lymphoproliferations : clinical and molecular aspects and differential diagnosis

Abstract

The studies presented in this thesis focused on cutaneous CD30-positive lymphoproliferations, particularly on primary cutaneous anaplastic large cell lymphoma (C-ALCL), a distinct type of cutaneous T-cell lymphoma (CTCL). In the initial staging of patients with an anaplastic large cell lymphoma first presenting in the skin, bone marrow examination has limited value (chapter 4). C-ALCL patients usually have an excellent prognosis, although some patients follow an unfavorable course. These patients often have extensive disease with leg involvement (chapter 2). Several phenotypical markers have been reported to aid in the differentiation between different types of cutaneous CD30-positive lymphoproliferations, however, TRAF1, MUM1 and BCL2 are not useful for this purpose (chapter 3). The miRNA expression profile of C-ALCL does show differences with that of tumor stage mycosis fungoides (MF), another type of CTCL, suggesting a different contribution to the pathogenesis of these lymphomas (chapter 5). In patients with transformed MF, several parameters can be used as prognostic factors, including CD30 expression, folliculotropic MF, extent of skin lesions and extracutaneous transformations (chapter 6).