CT findings of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease after allogeneic stem cell transplant

OBJECTIVE. We retrospectively analyzed the CT features of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease (GVHD) after allogeneic stem cell transplant (SCT). MATERIALS AND METHODS. We analyzed the CT features of late-onset noninfectious pulmonary complications in 14 patients with pathologic diagnoses of GVHD who survived disease free for more than 3 months after SCT. Late-onset noninfectious pulmonary complications were diagnosed by excluding pulmonary infection in these patients with respiratory symptoms and signs. The presence, extent, and distribution of CT features were evaluated in terms of geographic hypoattenuation, expiratory airtrapping, ground-glass attenuation (GGA), reticulation, crazy paving pattern, bronchiectasis, nodules, and honeycombing. Further disease classification was made on the basis of clinical, radiologic, and pulmonary function test results and histologic findings. The longitudinal changes of late-onset noninfectious pulmonary complications were followed with CT. RESULTS. The 14 patients with late-onset noninfectious pulmonary complications were classified into subgroups with bronchiolitis obliterans (BO) (n = 7), nonclassifiable interstitial pneumonia (n = 5), and combined BO and nonclassifiable interstitial pneumonia (n = 2). The CT features of nonclassifiable interstitial pneumonia were GGA (5/7, 71%), reticulation (4/7, 57%), and crazy paving pattern (4/7, 57%) with a peribronchovascular distribution (6/7, 86%). All patients with nonclassifiable interstitial pneumonia had progression of disease with an increased extent of traction bronchiectasis, reticulation, and honeycombing on follow-up CT scans (median follow-up period, 22 months). CONCLUSION. Although not commonly encountered, nonclassifiable interstitial pneumonia as a pattern of chronic GVHD should be included in the differential diagnosis of unexplained peribronchial GGA or progressive traction bronchiectasis after SCT.