Adult T-cell leukemia/lymphoma and cutaneous T-cell lymphoma. Are they related?

Comparative studies were performed on clinical and laboratory features of four patients with different types of T-cell lymphoma of the skin; adult T-cell leukemia/lymphoma (ATLL), Sézary syndrome, mycosis fungoides, and Ki-1-positive lymphoma. All neoplastic cells studied showed a helper-inducer T-cell phenotype. A Ki-1-positive lymphoma is distinct from other types of cutaneous lymphomas because of unique morphologic and phenotypic features. Clonal proliferation of lymphocytes infected by human T-cell lymphotrophic virus (HTLV)-1 distinguishes ATLL from other T-cell lymphomas of the skin, especially in the endemic area of ATLL. From the pathogenic point of view, ATLL should not be included in a group with mycosis fungoides and Sézary syndrome.