D103-05 Reversal of Lung Disease in a Case of Systemic AL Amyloidosis With Diffuse Alveolar-Septal Involvement

Abstract Introduction Amyloidosis with pulmonary involvement is a relatively uncommon occurrence often under-recognized with most diagnoses identified during autopsy. This case report outlines a patient with systemic AL amyloidosis with diffuse alveolar-septal involvement whose pulmonary function improved both clinically and radiographically with chemotherapeutic intervention targeting her underlying disease process. This has not been previously reported and would be considered unlikely as this patient had multiorgan involvement with severe lung disease at the time of diagnosis. Case A 74-year-old female with a pertinent past medical history of prior tobacco use of twenty pack years and seasonal allergies presented to the oncology clinic in November of 2022 after a skin biopsy was positive for primary amyloidosis. Diagnostic workup for amyloidosis was supportive of free lambda light chain monoclonal gammopathy of unknown significance (MGUS). Her PET scan was negative for lytic or hypermetabolic osseous lesions, however diffuse ground glass opacities were evident throughout both lung fields. Bone marrow biopsy showed a plasma cell neoplasm with five percent monoclonal lambda plasma cells involving a normocellular bone marrow. Fat pad biopsy stained positive for Congo red. Due to radiographic findings and report of worsening dyspnea, treatment with daratumumab, bortezomib, and dexamethasone (DVd) was started in January of 2023 targeting systemic AL amyloidosis. CT chest and pulmonary function tests (PFTs) were obtained and reviewed in January of 2023 (Figure 1). The PFTs revealed a moderate-severe restrictive lung disease with severely reduced diffusion capacity. Visualization of the airway with bronchoscopy was unremarkable and six transbronchial biopsies of the left lower lobe were obtained. Pathology returned with positive congo red staining confirming alveolar-septal pulmonary amyloidosis. Renal involvement was confirmed with biopsy in February of 2023. She achieved complete hematologic response in November of 2023 after starting treatment with dartumumab, lenalidomide, and dexamethasone three months prior. Remarkably, her pulmonary function improved in June of 2025 supported by both objective and subjective findings (Figure 1). Discussion This case report documents an atypical disease presentation and progression of systemic AL amyloidosis with diffuse alveolar-septal involvement and is the first case report to describe reversal of lung disease with chemotherapeutic intervention. There are limited reports of pulmonary amyloidosis available for review making guidance of most effective treatment regimen and expected disease progression sparse. Clinical suspicion must remain high to diagnose pulmonary amyloidosis at the earliest stage possible to improve patient outcomes. This abstract is funded by: None