Recurrent multiple lung lesions synchronizing with the disease activity of multiple myeloma

: A 68-year-old male patient, who was diagnosed with MGUS (IgG-λ) 11 years ago, was referred to our hospital because of a progressing pancytopenia. He was diagnosed with multiple myeloma (MM) and was hospitalized because of fever and pneumonia. Although empiric antibiotic and antifungal therapies were promptly initiated, his pneumonia worsened. Chest CT images revealed diffuse interstitial pneumonia. Although bortezomib/dexamethasone therapy was initiated as a treatment for MM and pneumonia, he showed little response. His pneumonia worsened and progressed to acute respiratory distress syndrome. Using mPSL (500 mg/day), sivelestat, and MM treatment switching to lenalidomide/dexamethasone (Rd), his respiratory status and CT findings rapidly improved. He received Rd therapy as an outpatient; however, after the completion of six cycles of therapy, his MM progressed, with a recurrence of pneumonia and high fever again. The onset of pneumonia was closely associated with MM progression. His pneumonia improved by treatment with mPSL half-pulse and MM treatment switching to carfilzomib/Rd. In the present study, we report the case of a patient with myeloma, who presented with multiple interstitial pneumonia, resulting in respiratory failure twice in concordance with myeloma progression.