The Sezary syndrome: hematologic criteria

Cutaneous T cell lymphoma (CTCL) is a heterogeneous group of lymphomas that present clinically in the skin and are believed to be neoplastic proliferations of T cells that comprise the skin-associated lymphoid tissue (SALT). The T-cells acquire adhesion molecules, such as the cutaneous lymphocyte-associated antigen, as a consequence of exposures of naive cells to antigens in the skin and lymph nodes draining the skin. This programs the resultant memory cells to circulate preferentially through the skin, regional nodes and back to the skin by way of the lymphatic vessels and blood. Neoplastic growth of these cells initially appear as skin lesions, followed later in the natural history by involvement of regional nodes and blood, often before evidence of more widespread involvement of internal organs.