Nodular Pulmonary Amyloidosis Mimicking Metastatic Pulmonary Nodules: A case report and review of the literature.

Amyloidosis is a disorder characterised by the extracellular deposition of amyloid, a fibrillary protein, in various organs such as the lungs. Pulmonary nodular amyloidosis can mimic other lung conditions that present with pulmonary nodules, such as metastasis, sarcoidosis and hyalinising granuloma. We report a 60-year-old man who presented to the Royal Hospital, Muscat, Oman, in 2017 with a history of shortness of breath upon exertion, orthopnoea and bilateral lower limb swelling. A chest X-ray showed bilateral nodular opacities. Enhanced chest computed tomography revealed bilateral pulmonary nodules with a predominantly perilymphatic and subpleural distribution, giving the impression of a neoplastic nodule. A histopathological examination of biopsied lung tissue confirmed a diagnosis of nodular pulmonary amyloidosis.