Adenoid cystic carcinoma of the tracheobronchial tree
Adenoid cystic carcinomas of the tracheobronchial tree are a type of low-grade tracheal tumour. They are considered to be the second most common primary tumour of the trachea.
They are usually first recognized in patients in their 40s. There is no recognised gender predilection.
Symptoms in patients with adenoid cystic carcinoma are usually related to airway obstruction and therefore includes dyspnoea, cough, stridor, wheezing, and haemoptysis.
The tumors may be histologically classified into tubular, cribriform, and solid subtypes 6. The tumours are usually low grade but may occasionally undergo high grade transformation 7.
Smoking appears to affect the incidence.
Adenoid cystic carcinomas usually arise in the lower trachea. Less commonly they are found in the mainstem bronchi, lobar bronchi and rarely, in the segmental bronchi and extrathoracic trachea.
On chest CT, these tumours have a notable tendency toward submucosal extension and typically manifests as either:
- intraluminal mass of soft-tissue attenuation with extension through the tracheal wall
- diffuse or circumferential wall thickening of the trachea, a soft-tissue mass filling the airway
- homogeneous mass encircling the trachea with wall thickening in the transverse and longitudinal planes
The longitudinal extent of the tumours are greater than their axial extent and the tumors usually involve more than 180° of the airway circumference.
They can be variable in shape ranging from polypoid to broad-based. Their margins are also variable and ranges from smooth to lobulated to irregular. Intratumoural calcification is rare.
- 1. Kwak SH, Lee KS, Chung MJ et-al. Adenoid cystic carcinoma of the airways: helical CT and histopathologic correlation. AJR Am J Roentgenol. 2004;183 (2): 277-81. doi:10.2214/ajr.183.2.1830277 - Pubmed citation
- 2. Hajdu SI, Huvos AG, Goodner JT et-al. Carcinoma of the trachea. Clinicopathologic study of 41 cases. Cancer. 1970;25 (6): 1448-56. Pubmed citation
- 3. Kim TS, Lee KS, Han J et-al. Sialadenoid tumors of the respiratory tract: radiologic-pathologic correlation. AJR Am J Roentgenol. 2001;177 (5): 1145-50. Pubmed citation
- 4. Lin C. Adenoid cystic carcinoma of the trachea and bronchus – a clinicopathologic study with DNA flow cytometric analysis and oncogene expression. Eur J Cardiothorac Surg. 2002;22 (4): 621-625. Eur J Cardiothorac Surg (full text) - doi:10.1016/S1010-7940(02)00406-2
- 5. Nomori H, Kaseda S, Kobayashi K et-al. Adenoid cystic carcinoma of the trachea and main-stem bronchus. A clinical, histopathologic, and immunohistochemical study. J. Thorac. Cardiovasc. Surg. 1988;96 (2): 271-7. Pubmed citation
- 6. Ishida T, Nishino T, Oka T et-al. Adenoid cystic carcinoma of the tracheobronchial tree: clinicopathology and immunohistochemistry. J Surg Oncol. 1989;41 (1): 52-9. Pubmed citation
- 7. Seethala RR, Hunt JL, Baloch ZW et-al. Adenoid cystic carcinoma with high-grade transformation: a report of 11 cases and a review of the literature. Am. J. Surg. Pathol. 2007;31 (11): 1683-94. doi:10.1097/PAS.0b013e3180dc928c - Pubmed citation