Diffuse chondroid malformation of the lung: cases series of a hitherto undescribed congenital lung disease.

Congenital chondroid lesions of the lung are rare pathological findings. They are a constant feature of lung malformations such as giant cystic pulmonary chondroid hamartoma, chondroid cystic malformation, and in the "cartilaginous variant" of congenital adenomatoid malformation. All of these present as a large single thoracic mass.We present the cases of three males and two females with hitherto undescribed diffuse chondroid lung disease, all but one of whom had neonatal respiratory distress syndrome with interstitial syndrome on chest radiograph. The pathological findings were similar in all patients, showing large areas of disorganized lung parenchyma containing diffusely distributed mature cartilage islands. With a mean follow-up of 6 years, all patients had a favorable outcome. This diffuse chondroid lung disease appears to be a new entity whose initial presentation mimicked interstitial lung disease without the usual clinical, radiological, and histological features. We speculate that it could be part of a clinical spectrum between malformative chondroid lung cyst and congenital pulmonary airway malformation.