Chapter 15: RECURRENT OR PERSISTENT PRIMARY HYPERPARATHYROIDISM, PARATHYROMATOSIS.

Persistent primary hyperparathyroidism is defined as the persistence or recurrence of hypercalcemia within 6 months of parathyroid surgery. Recurrent primary hyperparathyroidism is defined as the recurrence of primary hyperparathyroidism more than 6 months after an initially curative parathyroidectomy. In these situations, it is essential to rule out differential diagnoses, and in particular secondary hyperparathyroidism and familial hypocalciuric hypercalcemia. Failure to remove the pathological parathyroid gland or glands during initial surgery for primary hyperparathyroidism is the most common situation in non-expert centers. In other situations, genetically determined multi-glandular primary hyperparathyroidism must be screened for. More rarely, a second sporadic adenoma is identified, or, exceptionally, a parathyroid carcinoma or parathyromatosis. Effective morphological evaluation, combining a morphological and functional imaging, is essential prior to any new parathyroid surgery. The indications for surgery must be discussed in a multidisciplinary team, assessing the risk/benefit ratio, since the risk of surgical complications is higher. Revision surgery should be performed using a suitable approach, after laryngoscopy, in an expert center, ideally with intraoperative PTH measurement and recurrent nerve neuromonitoring.