Nodular amyloidosis of the lung presenting as lung malignancy

Abstract

Introduction. Amyloidosis is a disease associated with the extracellular deposition of insoluble protein material called amyloid. It can be acquired or hereditary, systemic or organ-limited. Nodular pulmonary amyloidosis is defined as one or more tumefactive amyloid deposits in the lungs. Outlines of cases. This study presents two cases that were hospitalized at the Institute for Pulmonary Diseases to clarify the origin of lesions detected on computed tomography (CT) scans of lung parenchyma. In the first case, in a 78-year-old woman, numerous non-calcified nodules were described on the chest CT. The patient died during hospitalization, and the autopsy revealed diffusely distributed greyish-yellow nodular lesions in the upper and middle parts of the right lung, as well as lesions in the form of partially calcified nodules in both lungs. Histological analysis of samples from macroscopically described nodules confirmed nodular amyloidosis. The second patient is male, 58 years old, who was operated on for rectal adenocarcinoma three years ago. A CT scan of the lung parenchyma shows a tumor nodule localized in the lower lobe and a nodular lesion localized in the upper lobe of the right lung. Histological analysis confirmed that the lesion from the lower lobe corresponds to the metastasis of colorectal cancer, while in the lesion from the upper lobe amyloid deposits were found. Conclusion. Pulmonary nodular amyloidosis is a rare condition, and because of the imaging similarities it is difficult to distinguish it from malignant nodules in the lung parenchyma. Therefore, as a part of routine practice, a definitive diagnosis of amyloidosis needs to be confirmed by tissue biopsy.