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.