{Reference Type}: Case Reports {Title}: Patient with Adult T-cell Leukemia and Lung Infection Caused by Mycobacterium abscessus: Successful Treatment with Intensive Chemotherapy Followed by Haploidentical Hematopoietic Stem Cell Transplantation. {Author}: Azumi H;Kubo M;Otani A;Ochi S;Kobayashi S;Miyataka Y;Nakamura F;Yagi H; {Journal}: Intern Med {Volume}: 63 {Issue}: 14 {Year}: 2024 Jul 15 {Factor}: 1.282 {DOI}: 10.2169/internalmedicine.1181-22 {Abstract}: A 63-year-old woman with adult T-cell leukemia (ATL) lymphomatous type developed a mild dry cough. Computed tomography revealed lung lesions with a tree-in-bud appearance during intensive chemotherapy. Antibodies against Mycobacterium avium complex were positive. Bronchoalveolar lavage culture showed growth of M. abscessus complex. Finally, M. abscessus subsp. massiliense was also identified. Sequential use of antimicrobials, including macrolides, was introduced during intensive chemotherapy, and the patient successfully underwent allogeneic hematopoietic stem cell transplantation (AHSCT). This is the first case report of a patient with ATL complicated by M. massiliense lung infection, who was successfully treated with haploidentical AHSCT using various combinations of antimicrobials.