This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Larynx, Subject name: ENT
Left-sided vocal cord palsy is commonly due to 
Select and explain. 
A. Left hilar bronchial carcinoma, B. Mitral stenosis, C. Thyroid malignancy, D. Thyroid surgery
A: Left hilar bronchial carcinoma
Answer: A: Left hilar bronchial carcinoma 
Explanation: Bronchogenic carcinoma is an impoant cause of left recurrent paralysis and should always be excluded by X-ray chest, bronchoscopy and biopsy unless the other cause is obvious. Other causes are Thyroid surgery Enlarged left auricle Intrathoracic surgery Thyroid disease (benign or malignant) Aoic aneurysm, Mediastinal lymphadenopathy Idiopathic Ref: PL Dhingra Textbook of Ear, Nose and Throat, Edition 6, page - 299