Pulmonary alveolar microlithiasis

An incidental finding in a patient with COPD

Abstract

Pulmonary alveolar microlithiasis is a rare hereditary disease caused by mutations in SCL34A2 gene that encodes for the phosphate cotransporter in type 2 alveolar cells. This results in an increase in phosphate and calcium in the lung surfactant leading to the formation and deposition of microliths intraalveolar. The definitive diagnosis requires the histological identification of the microliths. We report the case of a 67-year-old male patient with a history of COPD and heavy smoking, who consulted our institution for a progressive worsening of dyspnea a week prior, associated with dry cough and unquantified thermal rises at home. Chest radiography showed bilateral calcified micronodulations. High resolution computed tomography confirmed these findings. The diagnosis was confirmed by the histological results of bronchoalveolar lavage, where characteristic lamellar microliths were identified.