[Intraoperative management of undetectable parathyroid adenoma].

Despite new technologies and progress in parathyroid gland imaging, missed parathyroid adenomas are still a problem. In reoperations most adenomas were found in eutopic positions. Adenoma in atypical positions were mostly situated in the thymus or in the esophageal-tracheal groove. Positive parathyroid imaging can be helpful but does not necessarily result in a better success rate than conventional bilateral exploration by an experienced surgeon, which is > 95 %. The knowledge of anatomy and embryological development of parathyroid glands is most important. Intraoperative determination of parathyroid hormone levels can help localize the site of the adenoma. Thyroid resection should only be performed if preoperative or intraoperative ultrasound indicates a tumor in the thyroid gland. The most important factor for a successful parathyroid operation is an experienced surgeon.