Pulmonary alveolar microlithiasis with an unusual radiological pattern

Area of Science:

• Pulmonology
• Radiology
• Genetics

Background:

• Pulmonary alveolar microlithiasis (PAM) is a rare diffuse lung disease characterized by the accumulation of calcium phosphate microliths in the alveoli.
• It typically presents with a diffuse, sand-like pattern on chest imaging, often predominantly in the upper lung fields.
• The clinical presentation is variable, ranging from asymptomatic to severe respiratory failure.

Observation:

• A young, asymptomatic woman presented with an unusual radiological pattern of pulmonary alveolar microlithiasis.
• The imaging findings were characterized by a reticulonodular pattern predominantly in the lower lung fields, accompanied by Kerley B lines.
• This pattern deviates from the typical presentation of PAM.

Findings:

• Diagnosis was confirmed through a transbronchial lung biopsy, establishing the presence of microliths within the alveolar spaces.
• An asymptomatic brother of the patient exhibited the same unusual radiological pattern, suggesting a potential familial predisposition or genetic component.
• The lower lung field predominance and reticulonodular pattern with Kerley B lines represent an atypical manifestation of PAM.

Implications:

• This case highlights the importance of considering atypical presentations of pulmonary alveolar microlithiasis, even in asymptomatic individuals.
• The familial occurrence suggests a possible genetic basis for PAM, warranting further investigation into genetic factors.
• Recognizing unusual radiological patterns is crucial for timely diagnosis and management of rare lung diseases.