[An Autopsy Case Report of Adult T-cell Leukemia Accompanied by Rheumatoid Arthritis Mimicking Diffuse Panbronchiolitis].

A 50-year-old female with a history of chronic sinusitis and rheumatoid arthritis visited our department with repetitive lower respiratory tract infections of Pseudomonas aeruginosa. Her chest CT showed diffuse panbronchiolitis-like pulmonary lesions, her blood examination revealed atypical lymphocytes, and she was serologically positive for anti-human T-lymphotrophic virus type 1 (HTLV-1) antibody. Her rheumatoid arthritis had been well-controlled after biological agent treatment followed by anti-inflammatory analgesic treatment. She received long-term low-dose macrolide therapy for four years. The Pseudomonas aeruginosa gradually became multi-antibiotic-resistant. Her lower respiratory infection gradually became uncontrollable, and her adult T cell leukemia (ATL) developed to the acute phase. Due to repetitive lower respiratory tract infections and respiratory failure, however, she could not receive any treatment for ATL, and she eventually died due to the progression of the disease. An autopsy revealed an invasion of abnormal lymphocytes in multiple organs, including the lungs, which indicated that the HTLV-1 infection and the progression of ATL were the dominant factors in this patient's clinical course. There have been no diffuse panbronchiolitis-like cases accompanied by rheumatoid arthritis and HTLV-1 infection so far. Because these diseases show similar clinical features, it is difficult to discriminate between them. There are presently no appropriate criteria for the proper time of treatment of patients with pulmonary lesion-associated ATL, but further research is expected to elucidate this matter.