Amyloidosis of the lower respiratory tract. Clinical and pathologic features in a series of 21 patients.

Twenty one cases of amyloidosis of the lower respiratory tract were seen at a single center. In three patients, multifocal bronchial amyloid plaques led to stenosis and atelectasis, and in two, small pseudotumor masses were an incidental bronchoscopic finding. Two patients had nodular parenchymal amyloidosis, in one of whom the lesions were progressive and in the other static. Fifteen patients had diffuse parenchymal amyloidosis. Two of these had severe interstitial involvement and died in respiratory failure; eight had congestive cardiac failure, and parenchymal amyloidosis was a post-mortem finding; two had senile cardiorespiratory amyloidosis, also found at autopsy; and in three, the amyloidosis was associated with malignancy. The degree of respiratory embarrassment seemed to be related to the amount of amyloid in the gas diffusion zones, irrespective of the etiology of amyloidosis.