Abstract: Objective To investigate the clinical diagnosis, treatment, and prognosis of parathyroid adenoma(PA)with unilateral vocal cord paralysis as the first symptom and to facilitate accurate diagnosis and proper treatment. Methods The clinical data of one patient with unilateral vocal cord paralysis as the initial manifestation of PA were retrospectively analyzed, along with a review and discussion of the relevant literature. Results Recurrent laryngeal nerve injury can be caused by benign parathyroid adenoma compression. However, unilateral vocal cord paralysis as the initial and only manifestation of parathyroid adenoma is rare and difficult to detect. Parathyroid adenoma located in the middle-lower region of the dorsal thyroid lobe and the inferior thyroid artery may sandwich and pinch the recurrent laryngeal nerve, causing nerve swelling and, subsequently, vocal cord paralysis. Subjective and objective voice evaluation, in combination with laryngeal electromyography before and after the operation, revealed that accurate diagnosis, timely PA resection, and decompression of the recurrent laryngeal nerve can rescue nerve function and vocal cord movement. Additionally, these interventions can revert patient parathyroid hormone and blood calcium levels to normal. Conclusion PA rarely damage the recurrent laryngeal nerve. When unilateral vocal cord paralysis is its first and only symptom, PA can be easily misdiagnosed or remain undiagnosed. In patients with unilateral vocal cord paralysis, if a benign parathyroid tumor is found, the possibility of benign tumor compression and recurrent laryngeal nerve dysfunction should be considered, especially if the tumor is located in the middle-lower region of the dorsal thyroid lobe, where the inferior thyroid artery branches into the gland. Timely surgical resection and nerve decompression are the best choices of treatment.

Key words: Parathyroid adenoma, Unilateral vocal cold paralysis, Acoustic analysis, Recurrent laryngeal nerve