CRA8 NOT JUST ASTHMA: UNVEILING A HIDDEN ADENOID CYSTIC CARCINOMA OF THE LUNG

Jin Hong Vu, Sivasubramaniam A/L Balakrishnan, Sze Kye Teoh, Sin Nee Tan, Aishah Ibrahim, Soon Hin How
Hospital Tengku Ampuan Afzan, Kuantan, Pahang, Malaysia

Introduction
Adenoid cystic carcinoma is a rare salivary gland type of malignant neoplasm, but can occasionally originate in the tracheobronchial tree. Primary pulmonary ACC accounts for less than 1% of all lung cancers and is frequently misdiagnosed due to its indolent growth and nonspecific respiratory symptoms, often mimicking asthma.

Presentation
We report the case of a 26 years old lady with no smoking history who presented with a two year history of progressive wheeze, cough, and intermittent dyspnea, initially managed as bronchial asthma. Despite multiple courses of bronchodilators and corticosteroids, her symptoms persisted, with increasing frequency of exacerbations. Physical examination revealed wheezing over bilateral lungs. Chest radiograph was unremarkable, but spirometry showed a pattern of fixed airway obstruction. High resolution computed tomography of the thorax (HRCT) revealed a carinal mass causing luminal narrowing of distal trachea, carina, and complete obliteration of left proximal main bronchus. Rigid bronchoscopy revealed lower trachea occluded by mass with left crescent opening. Left main bronchus endoscopically occluded. Histopathological examination confirmed the diagnosis of adenoid cystic carcinoma.

Results
The patient underwent coring and a Y- silicone stent insertion. A multidisciplinary team meeting was carried out and plan for chemotherapy and radiotherapy.

Conclusion
This case illustrates how rare airway tumors can be mistaken for asthma, delaying appropriate management. Failure to respond to standard therapy should prompt clinicians to further evaluate with spirometry, imaging and bronchoscopy. A proactive diagnostic approach can significantly alter the patient’s trajectory by facilitating earlier and definitive treatment.