Pulmonary alveolar microlithiasis: A case report and brief review of literature

Background: Pulmonary alveolar microlithiasis (PAM), a rare autosomal recessive pulmonary disease, is mainly characterized by extensive calcium phosphate microliths deposition in the alveoli. The major mutation, causing the characteristic of this disease, occurs in solute carrier family 34 members 2 (SLC34A2), which is placed on chromosome 4p15.2. SLC34A2 encodes sodium-phosphate cotransporter type IIb, NPT2b, which plays a critical role in the transportation of phosphate ions from pulmonary alveoli into type II pneumocytes. Case Presentation: Herein, we have reported a 50-year-old male presented with recent sore throat, fever, and sweating. Radiological findings revealed bilateral micronodular pattern with diffuse ground glass attenuation in lower regions. Subsequent histologic examination of lung biopsy confirmed intra-alveolar accumulation of calculi and the diagnosis of PAM. In addition, we reviewed the literature narratively to clarify different aspects of PAM. Conclusion: In this paper, we presented a sporadic case of PAM which was suspected with chest x-ray and confirmed by HRCT and trans-bronchial lung biopsy. We hope that it can help clinicians to be more aware of this condition and make proper diagnosis.