Isolated Pulmonary Nodular Amyloidosis: A case report of a rare presentation of amyloidosis in the lung confused with bronchogenic carcinoma

Abstract

ABSTRACT

Isolated pulmonary amyloid is rare form of amyloidosis.  These proteins can be found in various locations throughout the body. Within the lungs, amyloid can be found diffusely in the lung parenchyma or in an isolated form. Amyloid proteins may also be deposited in the hilum, trachea or parenchyma of lung tissue. These uncommon diagnoses can be easily 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 a 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 light¹. 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 more benign process with more sinister prognosis of primary or secondary cancer can lead to great emotional turmoil for the patient and family. Prevention of a late diagnosis will also prevent inefficient use of money, time and medical resources. The aim of this case report is to increase the awareness of pulmonary amyloid presentations, and prevent a lengthy tumultuous diagnosis.