What is the most probable diagnosis for a middle-aged man with a neck lump that moves while swallowing?

The most probable diagnosis for a middle-aged man with a neck lump that moves while swallowing is indeed thyroid cyst. This movement during swallowing is characteristic of a thyroid lesion, particularly because the thyroid gland itself is located in the neck and attached to the surrounding structures, allowing it to move when the surrounding tissues do.

Thyroid cysts often present as palpable neck lumps and can be fluid-filled. They may exhibit mobility during swallowing due to the movement of the trachea and larynx, distinguishing them from other potential neck masses. Thyroid cancer, on the other hand, typically does not exhibit the same degree of mobility since it is often more fixed to surrounding structures and may present with other concerning symptoms such as compressive symptoms or cervical lymphadenopathy.

Pharyngeal pouch, also known as a Zenker's diverticulum, usually presents with symptoms like dysphagia or regurgitation rather than a mobile neck mass that can be palpated externally. Bronchus cancer is less likely to present as a neck lump and more commonly presents with respiratory symptoms, again making it less likely in this context.

By recognizing that a neck lump that moves with swallowing indicates a lesion associated with the thyroid, one can narrow down the diagnosis effectively toward thyroid cyst