Cody Pollock, Robin Gray, Alex Medellin
Isolated pulmonary amyloid is a rare form of amyloidosis. The hallmark of amyloid consists of abnormal insoluble proteins that deposit in various locations throughout the body. Within the lungs, amyloid proteins may be deposited in the hilum, trachea, or parenchyma of the lung, either distributed diffusely or in an isolated nodule. These uncommon diagnoses can be easly mistaken for less rare presentations. In the case of isolated pulmonary nodular amyloid, diagnosis of bronchogenic carcinoma, metastatic disease, and focal fungal infections such as tuberculomas and histoplasmomas are considered first. Amyloid is diagnosed only with a tissue sample reviewed by a pathologist using a Congo Red stain demonstrating apple-green birefringence under polarized light. Such tissue samples are made difficult to obtain due to the hard and nodular consistency of the amyloid protein layered in beta-pleated sheets. Confusion of this relatively commonly benign process with more sinister diagnosis of primary or secondary neoplasm can lead to great emotional turmoil for the patient and family. A late diagnosis will also prevent inefficient use of medical resources, money, and time. Increased awareness of the rare presentations of pulmonary amyloid may aid in preventing a lengthy and tumultuous arrival at a proper diagnosis.
KEYWORDS: focal nodular hyperplasia; ruptured tumor; liver resection; radiofrequency ablation
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Pollock C, Gray R, Medellin A. Isolated Pulmonary Nodular Amyloidosis: A Case Report of a Rare Presentation of Amyloidosis in the Lung Confused with Bronchogenic Carcinoma. UBCMJ. 2012 3(2):34-37.