Trajectory of lung function to pleuroparenchymal fibroelastosis late after haematopoietic stem-cell transplantation

Pleuroparenchymal fibroelastosis is characterized by upper lobes subpleural intra-alveolar fibrosis and elastosis with visceral pleural fibrosis, which may occur after allogenic haematopoietic stem-cell transplantation (HSCT). The longitudinal changes of lung function preceding this complication have not been described. We report the case of an adult woman undergoing allogeneic HSCT for Hodgkin's lymphoma. Pulmonary function tests evolved from normal, before transplantation, to a restrictive pattern with normal residual volume 3 months after transplantation, then to an obstructive pattern consistent with bronchiolitis obliterans 18 months after transplantation, and finally to a severe mixed pattern with preserved residual volume. Computed tomography showed the distinctive features of pleuroparenchymal fibroelastosis, confirmed by histology of specimen from apical resection after pneumothorax. This case report suggests that pleuroparenchymal fibroelastosis may occur after HSCT following bronchiolitis obliterans syndrome with a mixed (restrictive-obstructive) lung function pattern.