Recurrent hyperparathyroidism due to implantation of parathyroid tissue.

Recurrence of hyperparathyroidism after initially successful primary operation is usually caused by inadequate resection of diseased tissue or recurrent carcinoma. Since it is known that normal parathyroid tissue may be autotransplanted into a muscle bed, it is plausible that inadvertent implantation of parathyroid tissue spilled at operation may occur. In four of 23 reoperations for hyperparathyroidism in an 11 year period, we found evidence that iatrogenic parathyroid implantation had occurred. Two of the four patients had multiple parathyroid implants in the previous operative field, and one of these patients had documented spillage of a cystic adenoma during the original operation. Another two of the four patients were found to have recurrent adenomas containing suture material at sites of previous excision of the adenomas. No patient had gross or histologic evidence of parathyroid carcinoma. We conclude that inadvertently spilled parathyroid tissue may implant in the neck or mediastinum and cause persistent or recurrent hypercalcemia. Therefore, all efforts should be made to handle the parathyroid glands only by their pedicles and not to crush, suture, or violate the capsule. Needle aspiration of parathyroid cysts could lead to implantation along the needle tract.