Clinical and Pathologic features of North American/Caribbean Adult T-cell leukemia/lymphoma (ATLL), the Brooklyn, NY experience

Adult T-cell leukemia/lymphoma (ATLL) is a rare, highly aggressive, T-cell malignancy caused by human T-cell leukemia/lymphoma virus type 1(HTLV-1) infection.1 It is estimated that there are at least 5-10 million HTLV-1 carriers worldwide. Most of the HTLV-1 infection is thought to be acquired from mother-to-child transmission through breastfeeding. Sexual transmission and blood transfusion are other means of infection. Only a small number (2-5%) of HTLV-1 infected patients develop ATLL, usually after a long latency period (30-50 years after infection), suggesting additional genetic and epigenetic events are required for HTLV-1 infected cells to transform to ATLL. 2-3ATLL is endemic in certain regions where HTLV-1 infection is prevalent, including southwestern Japan, the Caribbean basin, areas of South America and tropical Africa.4 ATLL is rare in North America and the majority of the patients are immigrants from Caribbean basin, and rarely, of US-born African Americans. Studies have shown that HTLV-1 infection is prevalent in the black, predominantly Caribbean population of central Brooklyn, NY and that ATLL is endemic in this community. 5-7 Here we review the clinical and pathologic features of Caribbean ATLL and present our findings in a cohort of ATLL from central Brooklyn, NY. Our data suggest that Caribbean ATLL is not only clinically but also molecularly distinct from Japanese ATLL. Epigenetically targeted therapy may be a potential effective adjunct therapy in treatment of ATLL.