Nonspecific interstitial pneumonia pattern as pulmonary involvement in human T-cell lymphotropic virus type 1 carriers.

It is well established that diffuse interstitial shadows are observed in human T-cell lymphotropic virus type 1 (HTLV-1) carriers. However, the pathological pattern of nonspecific interstitial pneumonia (NSIP) has rarely been reported. Here, we describe the clinical features of four patients with histologically proven NSIP and HTLV-1 infection. The patients, one woman and three men, had a median age of 59.5 years. High-resolution computed tomography of the lungs was performed in all patients, and no apparent honeycomb formations were detected. The present study demonstrates that the NSIP pattern is a significant pathological classification of interstitial pneumonia associated with HTLV-1 carriers.