Question

Hoarseness secondary to bronchogenic carcinoma is usually due to extension of the tumour into

• A. Vocal cord
• B. Superior laryngeal nerve
• C. Left recurrent laryngeal nerve
• D. Right vagus nerve

Hint:

Think about which recurrent laryngeal nerve travels longest inside the chest.

Answer 1

The Correct Option is C

This question tests why lung cancer often causes a hoarse voice. The key lies in the path of the nerve that moves the vocal cords.

1. Vocal cord: The cord itself is rarely invaded directly by a lung tumour sitting in the chest, so this is not the usual route.
2. Superior laryngeal nerve: Damage here changes voice pitch and causes fatigue of the voice, not the classic hoarseness tied to lung cancer.
3. Left recurrent laryngeal nerve: This nerve dips down into the chest and loops under the aortic arch before climbing back to the larynx. That long detour through the chest puts it directly in the path of a bronchogenic carcinoma or its spread to mediastinal nodes.
4. Right vagus nerve: The right recurrent branch loops much higher, around the subclavian artery near the neck, away from most lung tumours, so it is rarely involved.

Because the left recurrent laryngeal nerve runs so far down into the chest, it is the structure most often trapped or invaded by lung cancer, and its damage paralyses the left vocal cord, producing hoarseness.

Let's summarize:

• The left recurrent laryngeal nerve has a long intrathoracic course under the aortic arch.
• This makes it the nerve most vulnerable to invasion by bronchogenic carcinoma.

So hoarseness from bronchogenic carcinoma is usually due to extension of the tumour into the left recurrent laryngeal nerve.