Localized amyloidosis of the lower respiratory tract

Tracheobronchial amyloidosis. The Boston University experience from 1984 to 1999

Tracheobronchial amyloidosis (TBA), an idiopathic disorder characterized by deposition of fibrillar proteins in the tracheobronchial tree, occurred in 10 patients referred to the Amyloid Program at Boston University over the past 15 years. Fewer than 100 cases of TBA have been described; only 1 series encompassed more than 3 patients. We analyzed our experience with biopsy-proven TBA to define better its natural history. Follow-up averaged approximately 8 years and was obtained in all cases, making this outcome reporting the largest and most complete to date. Three of these patients were prospectively studied for up to 24 months to examine the utility of bronchoscopy, computerized tomography (CT) imaging, and pulmonary function tests (PFTs) in monitoring disease progression. No patient with TBA developed signs or symptoms of systemic amyloidosis during the period reviewed. Conversely, tracheobronchial disease was not diagnosed in 685 patients with primary systemic (AL) amyloidosis during the 15-year study period at Boston University. Bronchoscopy proved most useful in establishing the diagnosis by biopsy. Narrowing of major airways limited its inspection of the tracheobronchial tree, however. In contrast, CT imaging provided quantitative assessment of airway narrowing and mural thickening--2 major consequences of amyloid infiltration. These CT features, in the presence of mural calcifications sparing the posterior tracheal membrane, have been reported in few disorders other than TBA. The ability of CT to map airway involvement and identify extraluminal manifestations of TBA made it the study of choice for establishing disease extent. Three patterns of disease were evident by CT imaging and bronchoscopic examination: proximal, mid, and distal airways involvement. Those with severe proximal disease had significantly decreased air flows, air trapping, and fixed upper airway obstruction on PFTs. Patients with distal disease had normal airflows. PFTs could not clearly distinguish proximal from severe mid airways disease. Thirty percent of patients died within 7-12 years after diagnosis, all having proximal or severe mid airways disease. Repeated rigid bronchoscopic debridement and laser treatments did not prevent progressive airways narrowing in patients dying from TBA. Most patients with mid airways involvement, and all distal airway cases, had either stagnant disease or slowly increasing amyloid deposits when followed for up to 14 years. In a small subset of patients followed prospectively, serial PFTs were most sensitive to disease progression. CT-derived measures of airway lumen diameter and wall thickness did not change significantly despite marked improvements in airflow after rigid bronchoscopy. Our experience suggests that serial PFTs and CT imaging together offer the best assessment of airway involvement and disease progression in patients with TBA. In the future, radiation therapy may provide more definitive treatment of TBA than debulking procedure have to date.

Treatment of endobronchial amyloidosis by intermittent bronchoscopic resection

In a patient with widespread endobronchial amyloidosis, the amyloid deposits resulted in severe disability over a ten-year period from obstruction of large airways and from recurrent chest infections and atelectasis. Repeated excision of small quantities of amyloid material during rigid bronchoscopy under general anaesthetic have resulted in symptomatic relief and measurable improvement of aiways obstruction.

Favourable outcome in a case of endobronchial amyloidosis

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Amyloid pseudotumor treated by tracheal resection

Primary amyloidosis is a rare disease, and even more so when it appears as a tumorlike formation in the lung or tracheobronchial tree. On rare occasions it has been treated by pulmonary resection but never before by tracheal or bronchial sleeve resection. A case of tracheal sleeve resection for tumorlike amyloidosis is reported. If the lesion is well circumscribed to a relatively short tracheal or bronchial segment, sleeve resection appears to be a satisfactory and economical solution. However, the problem of a mucosa undermined by amyloid deposits above and below the tumorlike lesion entails the risk of anastomotic stenosis. For this reason in future cases, particularly those with extensive involvement, piecemeal endoscopic removal should be considered as the method offering the best prognosis and least risk.

Primary amyloidosis of the respiratory tract

Two patients with solitary amyloidosis of the respiratory tract are discussed. Bronchial obstruction caused by amyloid deposits led to the death of our first patient. Diagnosis in the second patient was made after removal of a localized amyloid deposit within the lung parenchyma.

Pulmonary amyloidosis with impaired gas transfer

This is the report of a patient with multiple myelomatosis in whom secondary amyloid infiltration of the lung produced impairment of gas transfer and death from respiratory failure.

Primary diffuse tracheobronchial amyloidosis

The case is reported of a woman who died at the age of 36 years from obstructive respiratory failure due to diffuse tracheobronchial amyloidosis which had caused symptoms for six years. When first seen her symptoms of wheezing cough and mucopurulent sputum sometimes streaked with blood were of recent onset, but on bronchogram and bronchoscopy her disease was already widespread. Appearances at bronchography were interpreted as malformation and at bronchoscopy as tracheobronchitis, possibly tuberculous. Bronchoscopic biopsy was necessary to make the diagnosis of amyloidosis. The amyloid gave the usual staining reactions with an apple-green birefringence in polarized light following staining with Congo red. At necropsy an extensive histological survey proved that the amyloid was confined to the trachea and main stem bronchi. There was no associated disease, no family history, and no upset in plasma proteins.