Peribronchiolar Metaplasia of the Lung Incidentally Detected During a Surgery for Pneumothorax: A Case Report.

Background: Peribronchiolar metaplasia (PBM) is a lesion characterized by an abnormal connection between the terminal bronchiole and parabronchiole via the Lambert's canals. We report a rare case of PBM incidentally detected during a surgery for pneumothorax.

Case Presentation: At 38-year-old man was admitted to our hospital with chest pain. He was diagnosed with pneumothorax and treated using a thoracic drain 12 years ago. Chest computed tomography revealed a cyst in the right upper lobe and ground glass lesion with a solid component in the right lower lobe of the lung. Hence, we performed a surgery for pneumothorax management, which revealed a cyst in the right upper lobe and induration with angiogenesis in the right lower lobe. We performed partial resection of the right upper and lower lobes. Pathological examination of the lower lobe nodule revealed small airways with lymphocytic inflammation and bronchiolar metaplasia. Pathological diagnosis of the nodule was PBM.

Conclusion: Although PBM is considered a lesion with good prognosis, there have been cases associated with early-stage lung cancer. Hence, care should be taken to distinguish PBM from other neoplasms. However, preoperative diagnosis is difficult in most cases so complete surgical resection is recommended, if feasible.