Systemic AL amyloidosis presenting with diffuse alveolar septal involvement and respiratory failure: a case report and review of the literature

Abstract

BackgroundAmyloidosis is the extracellular deposition of amyloid fibril protein in any tissue or organ. The clinical manifestations of pulmonary amyloidosis are variable and without specific symptoms. We report a rare case of diffuse alveolar septal amyloidosis which is an extremely rare pattern of involvement, with a very poor prognosis, to improve our understanding of the disease.Case presentationA 27-year-old man complained of shortness of breath and cyanosis. High-resolution computed tomography revealed diffuse ground-glass opacifications with interlobular septal thickening in both lungs. The immune-histochemistry showed monoclonal lambda light chains. This case also showed nephrotic syndrome and cardiac arrhythmia, suggesting an involvement of the kidney and the heart. Diagnosis: The diagnosis was finally established by tru-cut transthoracic sonar guided lung biopsy (TSLB), and histological examination revealed Congo red-positive amorphous eosinophilic deposits in the alveolar sept. Interventions: The patient was admitted to a respiratory intensive care unit and put on non-invasive ventilation, then discharged on domiciliary oxygen therapy, and started treatment with chemotherapy melphalan 2 mg daily plus prednisone 60 mg daily immediately after the result of histopathology. Outcomes: Three months after treatment, dyspnea and hypoxemia improved, and he continued treatment. The patient was in a good clinical condition after 10 months of follow-up, but he died suddenly.ConclusionAs it is difficult to distinguish diffuse alveolar septal amyloidosis from other interstitial and granulomatous lung diseases because of their similar symptoms and imaging findings, thus, transthoracic sonar guided lung biopsy and histological examination is very important in the diagnosis of diffuse alveolar septal amyloidosis.