Tracheobronchial amyloidosis: an uncommon disease with a common presentation

Management of tracheobronchial amyloidosis: a review of the literature

Introduction

Tracheobronchial amyloidosis is a rare idiopathic disorder characterised by extracellular deposition of misfolded protein fibrils in the tracheobronchial tree. It presents with nonspecific symptoms. Deciding on the best treatment approach can be challenging due to the lack of a treatment guideline. We undertook a review to assess the therapeutic options for tracheobronchial amyloidosis and to highlight gaps within the existing evidence.

Methods

We performed a literature search from 1 January 1990 until 1 March 2022 to identify relevant literature regarding patient characteristics, symptoms, management and prognosis for patients with tracheobronchial amyloidosis.

Results

77 studies consisting of 300 patients were included. We found a great heterogeneity in the management of tracheobronchial amyloidosis patients. Although a fifth of the reported patients were managed with a wait-and-see approach, many different treatments were used as a single intervention, or multiple treatments were combined. An interesting finding is the slightly higher percentage of patients with Sjögren syndrome (n=5, 1.7%) and tracheobronchial amyloidosis compared to the normal population (0.5-1.0%).

Conclusions

There is a great heterogeneity in the management of tracheobronchial amyloidosis patients. The treatment is still based on expert opinion due to the lack of a treatment guideline. Various treatment approaches include a wait-and-see approach, external beam radiotherapy, therapeutic bronchoscopy, immunosuppressive treatment and surgery.

Primary Tracheobronchial Amyloidosis Presenting with an Upper Airway Obstruction

This is a case of localized primary tracheobronchial amyloidosis in a patient who presented with upper airway obstruction. Tracheobronchial amyloidosis is a type of localized bronchopulmonary amyloidosis that is frequently overlooked. It involves the deposition of amyloid protein on the tracheal and bronchial tissue, leading to progressive tracheal stenosis and airway obstruction that can be seen on imaging as a tracheal mass. Because of its significant diagnostic difficulty and therapeutic conundrum, it ought to be considered in the differential diagnosis of upper airway symptoms with an unknown etiology.

Pulmonary manifestations of amyloidosis

Amyloidosis is caused by abnormal protein deposition in various tissues, including the lungs. Pulmonary manifestations of amyloidosis may be categorized by areas of involvement, such as parenchymal, large airway and pleural involvement. We describe four distinct manifestations of amyloidosis involving the lung and review their clinical, radiological and pathological features and summarize the evidence for treatment in each of these presentations. We describe alveolar-septal amyloidosis, cystic amyloid lung disease, endobronchial amyloidosis and pleural amyloidosis.

Tracheobronchial Amyloidosis Accompanied with Asthma: A Case Report and a Mini-Review

Tracheobronchial amyloidosis is a rare disease characterized by amyloid deposits on the tracheal and bronchial tissue. Patients with tracheobronchial amyloidosis are asymptomatic or exhibit symptoms, such as chronic wheezing, dyspnea, and cough, that are common manifestations of other disorders, including asthma. A bronchoscopic tissue biopsy using Congo red staining is the key standard for diagnosing tracheobronchial amyloidosis. Treatment strategies vary depending on the degree of airway obstruction. If the obstruction is significant and the patient is symptomatic, repeated bronchoscopic treatment, including local resection, laser therapy, stent placement, and radiation therapy, is considered a safer and better option. It is often misdiagnosed as asthma, but cases of tracheobronchial amyloidosis accompanied with asthma have not been reported. We report a case of intermittent wheezing, cough for 33 years, and shortness of breath on exertion for 7 years, which had aggravated in the previous 22 days. A pulmonary examination revealed diffuse wheezing. Pulmonary function testing revealed an obstructive ventilation dysfunction. Computerized tomography (CT) imaging revealed circumferential and irregular thickening of the tracheobronchial wall tissue with calcification and atelectasis of the right middle and lower lobe of the lung. Bronchoscopy revealed diffuse thickening of the mucosa of the trachea and bilateral main bronchi, with multiple nodular protuberances and relatively narrow lumens. The bronchial biopsies revealed massive amyloid deposits under the bronchial mucosa. The deposits exhibited a green birefringence under crossed polarized light after Congo red positive staining. The patient received standard treatment for asthma, and remains in good general condition without wheezing. It is not difficult to distinguish tracheobronchial amyloidosis through chest CT examination for patients with wheezing as long as this disease was considered. It was interesting that we present a rarer case of patient with tracheobronchial amyloidosis accompanied with asthma which both can cause symptoms such as wheezing.

Tracheobronchial amyloidosis: A case report and review of literature

Tracheobronchial amyloidosis, manifested by amyloid deposits limited specifically to tracheal and bronchial tissue, is a rare manifestation with only a few hundred published cases. Patients classically present with symptoms related to fixed upper airway obstruction caused by tracheal stenosis. Clinical symptoms are non-specific and include hoarseness, dyspnea, cough, stridor, hemoptysis, and dysphagia, which are similar to those caused by more common airway disorders, often leading to incorrect, missed, and delayed diagnosis. The wide-spread use of computerized tomography (CT) imaging has the potential of dramatically advancing the early diagnosis of tracheobronchial amyloidosis. We present a case of a patient with chronic and progressive hoarseness, diagnosed with tracheobronchial amyloidosis, with a focus on unusually clear and precise CT soft tissue neck imaging. CT imaging demonstrated nodular circumferential raised mass-like thickening involving the long-segment posterior wall of the distal trachea. The wall thickening also extended into the proximal left main stem bronchi, but spared the distal bronchial tree. This resulted in moderate (approximately 50%) narrowing of the tracheal lumen, which explained the patient's hoarseness. Routine CT imaging of patients with chronic and progressive respiratory symptoms, including cough, hoarseness, and dyspnea, is recommended. Tracheobronchial amyloidosis is an uncommon disease, but it may become more commonly recognized with broader use of more effective CT imaging protocols.