Pulmonary alveolar microlithiasis diagnosed with radiography, CT, and bone scintigraphy.

Pulmonary alveolar microlithiasis is rare disease characterized by accumulation of calcium phosphate microlithis in the alveoli. The pathogenesis relates to mutation in the gene SLC34A2 (solute carrier family 34 member 2) located on chromosome 4p15.2, which produces a defective sodium-phosphate cotransporter in alveolar epithelial type-2 cells, making these cells unable to clear phosphorus released during recycling of surfactant [1].

Concurrent smoking-related interstitial lung diseases in a single patient.

The three smoking-related interstitial lung diseases (ILD) include desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and pulmonary Langerhans cell histiocytosis (PLCH). They are considered discrete entities, yet it is not unusual to find a mixture of pathologic features rendering the histopathologic diagnosis difficult. It is uncommon to have overlap in the different radiologic findings between these diseases.