Secondary Hyperparathyroidism Presenting with Vocal Cord Paralysis

Abstract

ABSTRACT The association of vocal cord paralysis with tumors in the neck generally raises the suspicion of an underlying malignancy. We report the clinical course, imaging and operative findings in a patient with secondary hyperparathyroidism presenting with vocal cord paralysis. The related literature is also reviewed. A 45-year-old man with end-stage renal failure was awaiting surgical treatment for secondary hyperparathyroidism. Ultrasound of the neck demonstrated hypoechoic nodules consistent with enlarged parathyroid glands. Several months later, just before the scheduled date for parathyroid surgery, he developed increasing hoarseness and vocal fatigue. Direct laryngoscopy revealed an immobile left vocal cord (VC). Neck examination and further imaging did not reveal the source of VC palsy. A presumptive diagnosis of thyroid or parathyroid malignancy involving the recurrent laryngeal nerve (RLN) was made. Intraoperatively, four enlarged parathyroid glands were encountered. The left superior gland was seen stretching and displacing the RLN without evidence of direct invasion. This was successfully dissected off while preserving the RLN. The remaining three parathyroid glands were subsequently removed with autotransplantation of a parathyroid remnant. In addition, a left thyroid lobectomy and ipsilateral level VI dissection was performed. Final pathology revealed parathyroid hyperplasia and thyroid follicular adenoma. No malignancy was seen. Three weeks later, the patient's biochemistry had normalized and his voice improved. Laryngoscopy confirmed a mobile left VC. Benign parathyroid tumors are rarely associated with RLN compression leading to VC paralysis. Such diagnoses are difficult to make preoperatively. In the absence of malignant invasion, the RLN should be preserved during surgery as it is likely to recover once the compression is relieved.