Molecular pathogenesis of cutaneous lymphomas.

Primary cutaneous T-cell lymphoma (CTCL) comprises the second most common group of extra-nodal non-Hodgkin's lymphoma. They represent incurable primary extra-nodal lymphomas of major T cells, uniformly present in the skin with 1%-2% risk of systemic dissemination in mycosis fungoides (MF), which represents the most common subtype of CTCL. In general, long-term antigen stimulation is thought, through key cytokine signalling pathways, to induce an inflammatory response with T-cell proliferation, leading to a clonal malignant T cell with continuous expansion. However, in recent years, using data harvested from high-throughput transcriptional profiling, substantial advances in the understanding of the molecular pathogenesis were made to understand the complex pathogenesis of CTCL. In this review, the actual data are summarised.