JSH Practical Guidelines for Hematological Malignancies, 2018: II. Lymphoma-8. Adult T-cell leukemia–lymphoma

Adult T-cell leukemia–lymphoma (ATL) is a disease concept first described by Uchiyama and Takatsuki et al. in 1977 as a T-cell neoplasm endemic to southwestern Japan, primarily the Kyushu region and Okinawa [1]. Human T-cell leukemia virus type 1 (HTLV-1) was discovered as the causative virus in the early 1980s [2–5]. In the 2017 WHO Classification, ATL is defined as a peripheral T-cell neoplasm caused by HTLV-1 that is composed of lymphocytes with high-grade nuclear atypia [6].

Clinical presentation includes leukocytosis primarily characterized by proliferation of abnormal lymphocytes called flower cells, lymphadenopathy, skin lesions, multiple organ dysfunction due to invasion by ATL cells, elevated blood LDH, hypercalcemia, and opportunistic infections. Outside of Japan, ATL is relatively common in people from central Africa and Central and South America. There are about 1.1 million HTLV-1 carriers in Japan, primarily on the southwestern coast, and the annual incidence of...