Primary tracheobronchial amyloidosis. A case report and review of reported cases

A case of diffuse tracheobronchial amyloidosis in a 70-year-old woman thought clinically at first to have lung carcinoma is reported. Bronchoscopic biopsy was necessary to make a diagnosis. Amyloid was deposited markedly in the subepithelial layer. After Congo-red staining amyloid showed the usual apple-green birefringence under polarizing microscope. Electron microscopic study disclosed typical amyloid fibrillar structure. Amyloid protein of this patient was confirmed to be AL protein by immunoperoxidase study which showed specific staining by the anti-A lambda antiserum. When potassium permanganate reaction was used amyloid protein of this patient resisted to the reaction. We reviewed 19 cases from the previously reported cases of primary amyloidosis of the lower respiratory tract, and gave some description of pathologic and clinical aspects of this disease.