Pulmonary alveolar microlithiasis

This code signifies a rare, chronic lung disease characterized by the widespread deposition of tiny calcium phosphate stones (microliths) within the alveoli. These calcifications progressively impair gas exchange and can lead to restrictive lung disease. The condition is often asymptomatic for many years before respiratory symptoms develop.

Use this code when documentation confirms the diagnosis of pulmonary alveolar microlithiasis, typically identified through chest imaging (e.g., X-ray, CT scan showing diffuse, fine granular opacities) and sometimes confirmed by lung biopsy. This code is appropriate for both initial diagnosis and subsequent encounters for management of the condition.

• Ensure documentation clearly specifies "microlithiasis" to differentiate from other forms of pulmonary calcification.
• Do not confuse with other interstitial lung diseases unless alveolar microlithiasis is explicitly stated.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter, especially for diagnostic workup or management of its complications.