Patterns of pulmonary involvement in systemic amyloidosis

Area of Science:

• Pulmonary Medicine
• Pathology

Background:

• Systemic amyloidosis frequently involves the lungs, but clinical significance varies by type.
• Pulmonary involvement can be asymptomatic or a primary cause of mortality.

Purpose of the Study:

• To review the clinical and histopathologic features of pulmonary amyloidosis in patients with systemic amyloidosis.
• To determine the frequency and patterns of lung involvement across different types of systemic amyloidosis.

Main Methods:

• Retrospective review of autopsy cases (n=22) with systemic amyloidosis.
• Histopathologic examination of lung tissue, including Congo-red staining and polarized light microscopy.

Main Results:

• 92% of primary amyloidosis cases showed interalveolar deposits; 33% had symptoms.
• Amyloidosis with multiple myeloma/Waldenstrom's macroglobulinemia showed extensive deposition.
• 71% of secondary amyloidosis cases had perivascular/tracheobronchial involvement, without symptoms.

Conclusions:

• Pulmonary amyloidosis is a frequent finding in systemic amyloidosis, regardless of type.
• Lung biopsy with Congo-red staining is recommended for unexplained pulmonary disease to detect amyloid.
• Histologic lung involvement is common, but clinical manifestation varies, necessitating careful diagnostic evaluation.