Novel SLC34A2 mutation in a patient with pulmonary alveolar microlithiasis associated with cholelithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare autosomal recessive lung disorder caused by SLC34A2 mutations, leading to intra-alveolar calcium phosphate microlith deposition. We report a case of a woman in her 60s who was incidentally diagnosed with PAM during preoperative evaluation for cholelithiasis. High-resolution CT of the thorax revealed bilateral diffuse calcific micronodules. Bronchoalveolar lavage and transbronchial lung biopsy confirmed the presence of intra-alveolar microliths. Genetic analysis identified a novel homozygous missense mutation in exon 6 of the SLC34A2 gene (p.Gly187Arg), not previously reported in the literature. The patient subsequently underwent laparoscopic cholecystectomy and remained asymptomatic from a respiratory perspective at the 6-month follow-up. This case highlights that coordinated interpretation of radiological, pathological and genetic findings is essential to establish a diagnosis of rare pulmonary disease.