Non-recurrent Laryngeal Nerve: A Rare Encounter During Thyroidectomy

The recurrent laryngeal nerve (RLN) is at risk during thyroid surgery. It innervates all intrinsic laryngeal muscles except the cricothyroid. Injury to the RLN can result in significant morbidity, including vocal cord paralysis. The non-recurrent laryngeal nerve (NRLN) is a rare anatomical variant that does not follow the typical recurrent course, entering the larynx directly from the vagus nerve. Its presence increases the risk of iatrogenic injury, particularly if not identified intraoperatively.We report the case of a 56-year-old woman who presented with a longstanding anterior neck swelling, clinically diagnosed as a benign multinodular goitre. Preoperative investigations, including ultrasound and FNAC, confirmed benign pathology, and thyroid function tests were normal. She underwent an elective total thyroidectomy. During the procedure, the left RLN was identified in its typical anatomical position, but on the right side, the RLN was not visualised in its usual recurrent location. Suspecting a non-recurrent variant, a careful dissection was performed between the larynx and carotid sheath. A right-sided NRLN was identified entering the larynx at a right angle directly from the vagus nerve. The surgery was completed without complications, and the patient had an uneventful recovery with no vocal or calcium-related issues.Awareness of the possibility of a non-recurrent laryngeal nerve is essential during thyroidectomy, especially when the RLN is not identified in its usual anatomical course. Early recognition through cautious dissection and anatomical knowledge is key to preventing nerve injury and ensuring patient safety.