[Bronchial adenoid cystic carcinoma masquerading as bronchial asthma: a case report]

Here we reported a case of bronchial adenoid cystic carcinoma from Peking University Third Hospital. A 40-year-old female presented with dry cough for 1 year and nocturnal paroxysmal attacks of wheezing for 4 months. She was a non-smoker, and did not have past histories of asthma or allergy. On physical examination, no stridor, wheezing and cyanosis were present and the general appearance was good. The results of the laboratory analysis, including blood eosinophils count, immunoglobulin E level and chest X-ray were normal. Spirometry revealed reversible airflow obstruction, and post-bronchodilator forced expiratory volume in one second (FEV1) showed an increase of 12% and 230 mL from baseline. Bronchial asthma was diagnosed, however, she responded poorly despite the adequate anti-asthma therapy including high dose inhaled corticosteroid plus long-acting beta2-agonist, theophylline and montelukast. Then chest computed tomography (CT) was performed which showed a polypoid mass occupying the lumen of left main bronchus. Then the bronchoscopy revealed a polypoid endo-bronchial mass arising from the left main bronchus, causing subtotal obstruction of the lumen. Biopsy was carried out through the bronchoscopy, the pathological findings showed characteristic cribriform and tubular pattern which was formed by two-layered cells with ductal and myoepithelial phenotypes, which were consistent with adenoid cystic carcinoma. Re-examining the patient, the lung was clear without any wheeze when she was seated. However, inspiratory wheeze was heard in her left upper lung when she was supine, and disappeared after sitting up again. Subsequently the patient underwent a resection surgery. At the operational site, the tumor was seen on the anterolateral wall of the left main bronchus, without submucosally expanding histologically. Therefore, a sleeve resection surgery of the left main bronchus was performed. Following surgery, chest CT scan revealed complete resolution of the tumor. Her symptoms improved significantly, as did her pulmonary function tests, although all the medicines for asthma were stopped. Now, two years after the operation, the patient remained asymptomatic, and spirometry was performed again which showed normal completely. The presenting case report emphasizes the fact that not all wheezes and reversible airflow obstruction are asthma. It is critical to bear in mind that if a "difficult asthma" patient does not respond to appropriate anti-asthma therapy; localized obstructions should be differentiated.