Abstract Introduction Systemic light-chain (AL) amyloidosis is a rare plasma cell disorder characterized by extracellular deposition of misfolded immunoglobulin light chains, leading to multiorgan dysfunction. Cardiac involvement occurs in up to 70% of cases and predicts poor survival, whereas pulmonary involvement is uncommon (10%) and may mimic interstitial lung disease (ILD), sarcoidosis, or drug-induced pneumonitis. Early recognition is essential for appropriate management. Case Description A 72-year-old male with hypertension, hyperlipidemia, nonobstructive coronary artery disease, and persistent atrial fibrillation presented with progressive dyspnea and fatigue over six months. Pulmonary function testing demonstrated restriction, and cardiac studies were consistent with systemic amyloidosis. Cardiac imaging revealed concentric left ventricular hypertrophy with restrictive filling and diffuse late gadolinium enhancement on MRI. High-resolution CT of the chest showed mediastinal lymphadenopathy, bilateral pleural effusions, and patchy ground-glass opacities. Bone marrow and abdominal fat pad biopsies confirmed systemic AL amyloidosis. Bronchoscopy with endobronchial biopsy and EBUS-guided lymph node aspiration revealed Congo red-positive amyloid deposits, confirming pulmonary involvement. No granulomas were identified, making sarcoidosis unlikely. Transthyretin genetic testing was deferred given histologic confirmation of AL subtype. The patient was discharged for outpatient follow-up with pulmonology and hematology/oncology while receiving bortezomib-based chemotherapy. Discussion Diffuse pulmonary involvement in AL amyloidosis is rare and can mimic ILD or granulomatous disease. Tissue diagnosis via advanced bronchoscopic sampling was critical to distinguish amyloidosis from alternative etiologies. Multidisciplinary collaboration among pulmonology, cardiology, and hematology enabled timely diagnosis and therapy. Pulmonary involvement contributed to dyspnea and functional limitation, underscoring the importance of early recognition and coordinated care. Conclusion Pulmonary AL amyloidosis should be considered in patients with unexplained interstitial patterns and restrictive cardiomyopathy. Histologic confirmation and integrated cardiopulmonary-hematologic evaluation are essential for accurate diagnosis and management. Impact Statement Advanced bronchoscopic sampling is vital for diagnosing rare pulmonary manifestations of systemic AL amyloidosis and highlights the value of multidisciplinary care. Learning Objectives 1. Recognize pulmonary AL amyloidosis as a rare cause of interstitial lung patterns. 2. Understand the role of bronchoscopy and EBUS-guided biopsy in diagnosis. 3. Appreciate the need for integrated cardiopulmonary-hematologic management. This abstract is funded by: None
Bansal et al. (Fri,) studied this question.