Nodular Pulmonary Amyloidosis with Interstitial Lung Disease—Case Report and Literature Review

Amyloidosis is a rare spectrum of disease which involves deposition of misfolded extracellular proteins (amyloids) in various body organs leading to progressive organ dysfunction. Clinical presentation can be variable depending on the organ involved and type of protein. Amyloidosis can be classified based on quantity, type, and location of these proteins. Amyloid light-chain amyloidosis develops in the bone marrow, producing abnormal forms of light-chain proteins, which cannot be broken down. These proteins transform into amyloid fibrils and form amyloid deposits in different organs. Pulmonary amyloidosis is uncommonly diagnosed since it is rarely symptomatic. Diagnosis of pulmonary amyloidosis is usually made in the setting of systemic amyloidosis; however, it may present as localised pulmonary disease. Localized pulmonary Amyloidosis can present as nodular, cystic, or tracheobronchial amyloidosis. Depending on the degree of the interstitial involvement, it may affect alveolar gas exchange and cause respiratory symptoms. This is a case of a 47-year-old female with background history of interstitial lung disease presenting with progressive shortness of breath. Computed tomography scan revealed bilateral pulmonary nodules. The patient was referred to our thoracic surgery team with the suspicion of bronchogenic malignancy with metastasis. Diagnostic video assisted wedge resection was performed for this patient, and histology confirmed pulmonary amyloidosis of nodular type. Amyloid deposition simulates both inflammatory and neoplastic conditions. Definitive diagnosis requires biopsy confirmation therefore early detection and commencing the patient on appropriate treatment pathway may help in symptomatic relief and better outcome.