Pulmonary alveolar microlithiasis with homozygous c.316G > C (p.G106R) mutation: a case report.

Pulmonary alveolar microlithiasis is characterized by the presence of calcospherites in alveolar spaces. Sporadic cases are more common, but the disease also presents in an inherited familial form. The greatest number of reported cases is from Europe and especially Turkey. We present a 43-year-old female with complaints of dyspnea for many years. She had a suspicious familial history of pulmonary alveolar microlithiasis. The surgical lung biopsy specimen appeared gritty and firm. Histological sections showed diffuse involvement of the lung parenchyma by innumerable tiny calcospherites. Genetic studies showed a homozygous c.316G > C (p.G106R) mutation in exon 4 and confirmed the diagnosis of pulmonary alveolar microlithiasis. The present report aims to contribute to the literature with a pathologically and genetically confirmed new case to add insight into the etiology of this rare disease. This case confirms an autosomal recessive inheritance and does not support the role of non-genetic and other factors in the pathogenesis of pulmonary alveolar microlithiasis.