The airway can be affected by primary tracheobronchial tumors, primary tumors that are adjacent to and invade or compress the airway, or cancers that metastasize to the airway.
Primary tracheal tumors are rare. They are often malignant and found at a locally advanced stage. Other tumors (eg, thyroid, lung) can locally invade the airways.
The most common malignant tracheal tumors include
Adenoid cystic carcinoma
Squamous cell carcinoma
Carcinoid
Mucoepidermoid carcinomas
The most common benign airway tumor is a
Squamous papilloma (most often related to human papillomavirus)
Pleomorphic adenomas and granular cell and benign cartilaginous tumors also occur.
Symptoms and Signs of Airway Tumors
Patients often present with
Dyspnea
Cough
Wheezing
Hemoptysis
Stridor
Hemoptysis, while uncommon, more often occurs with a squamous cell carcinoma and can potentially lead to earlier diagnosis, whereas wheezing or stridor occurs more often with the adenoid cystic variant. Dysphagia and hoarseness can also be present initially and usually indicate advanced disease.
Diagnosis of Airway Tumors
Bronchoscopic biopsy
Symptoms of airway narrowing (eg, stridor, dyspnea, wheezing) can herald life-threatening airway obstruction. An airway tumor should be considered a possible cause if such symptoms are unexplained, are of gradual onset, are associated with other symptoms of airway tumors (eg, unexplained hemoptysis), and respond poorly to standard treatments (eg, if aggressive asthma treatments do not relieve wheezing, or antibiotics for apparent pneumonia do not reduce symptoms and improve x-ray findings).
If an airway tumor is suspected, patients require immediate evaluation with bronchoscopy. Bronchoscopy can both treat airway obstruction and allow specimens to be obtained for diagnosis. If cancer is found, more extensive testing is done for staging.
Treatment of Airway Tumors
Surgery
Sometimes radiation therapy
Obstruction reduction techniques
Primary airway tumors should be treated definitively with surgical resection if possible. Tracheal, laryngotracheal, or carinal resections are the most common procedures. Up to 50% of the length of the trachea can be safely resected with primary reanastomosis. If a lung or thyroid cancer invades the airway, surgery is sometimes still feasible if assessment indicates sufficient tissue is available for airway reconstruction. Adjuvant radiation therapy is recommended if adequate surgical margins cannot be obtained.
Most primary airway tumors are not resectable because of metastasis, locally advanced stage, or patient comorbidities. In cases of endoluminal tumors, therapeutic bronchoscopy can mechanically core-out the tumor. Other techniques to eliminate obstruction include laser vaporization, photodynamic therapy, cryotherapy, and endobronchial brachytherapy. Tumors that compress the trachea are treated with airway stenting, radiation therapy, or both.
Prognosis for Airway Tumors
Prognosis depends on the histology.
Squamous cell carcinomas tend to metastasize to regional lymph nodes and directly invade mediastinal structures, leading to high local and regional recurrence rates. Even with definitive surgical resection, the 5-year survival is < 40% (1).
Adenoid cystic carcinomas are typically indolent but tend to metastasize to the lungs and to spread perineurally, leading to high recurrence rates after resection. However, these patients have a 5-year survival of about 60 to 75% because of the slow tumor growth rate.
Prognosis reference
1. Gaissert HA, Grillo HC, Shadmehr MB, et al: Long-term survival after resection of primary adenoid cystic and squamous cell carcinoma of the trachea and carina. Ann Thorac Surg 78(6):1889-1897, 2004. doi:10.1016/j.athoracsur.2004.05.064
Key Points
Primary tracheal tumors are rare, often malignant, and commonly locally advanced when recognized.
Suspect airway tumors in patients with gradual, unexplained, or intractable dyspnea, cough, wheezing, hemoptysis, and stridor.
Hemoptysis may occur but is uncommon and typically is from squamous cell carcinoma
Treat with local resection or, if resection is not indicated, other locally destructive therapies.
