Prevalence of subclinical pulmonary transthyretin amyloidosis in a pathology-based elderly cohort: the diagnostic value of routine amyloid staining.

While cardiac transthyretin amyloidosis is increasingly recognized in older adults, it remains unclear whether similarly frequent deposition occurs in the lungs. This retrospective study aimed to investigate the prevalence of pulmonary transthyretin amyloidosis (PTA) in the general elderly population. Among consecutive 274 patients aged ≥75 years who underwent lung resection, five cases of PTA were identified by histological examination (prevalence 1.8 %). These patients were asymptomatic without obvious radiological abnormalities in the background lung. Histopathology revealed scattered transthyretin-positive amyloid deposits in alveolar septa with minimal architectural distortion, which was frequently difficult to detect on hematoxylin & eosin staining alone. Subclinical PTA is not uncommon in elderly individuals and routine amyloid/transthyretin staining may be helpful.