Dohi memorial lecture. Cutaneous T cell lymphoma.

Abstract

AbstractCutaneous T cell lymphoma (CTCL) is a generic classification of clonally‐derived malignancies of phenotypic helper/inducer T cells with a propensity to infiltrate the skin, migrate into the epidermis, localize in T cell zones of lymphoid structures and spare the bone marrow. One clinical presentation has a tendency to evolve into another as subclones of progressively less mature and less epidermotropic neoplastic cells arise and overgrow the relatively more mature other subclones. In this manner, localized, scaling plaques of typical parapsoriasis develop into more infiltrated plaques of classical mycosis fungoides which are themselves predecessors of tumor or erythroderma stage CTCL. With loss of epidermotropism, systemic dissemination occurs: first microscopically with blood involvement and seeding of internal organs and finally with visceral tumor formation. The relationship between CTCL and adult T cell lymphoma/leukemia is unclear because of tremendous overlap in the clinical and immunologic findings and because a fraction of patients with classical CTCL have low titers of anti‐HTLV‐1 antibodies. It is important to distinguish the skin‐limited and systemic phases of CTCL in order to select appropriate treatments. New diagnostic techniques which are quite helpful include immunotyping with monoclonal antibodies, karyotype analysis and T cell receptor studies. Photopheresis, a very promising new therapeutic approach for the management of patients with systemically disseminated disease, and a suggested pathogenetic scheme are discussed.