What should be the first step if only 3 parathyroids are identified in a case of 4 gland hyperplasia?

When encountering a case where only three parathyroid glands are identified in a suspected four-gland hyperplasia scenario, the first step should involve checking the carotid sheath. The parathyroid glands can sometimes be ectopic or located in unexpected positions. The carotid sheath is a common location where a fourth parathyroid gland may be found when it has migrated from its normal anatomic position.

During surgery, it's essential to consider ectopic locations, as these variants can lead to persistent primary hyperparathyroidism if not identified and removed. A gland may be located along the path of migration of parathyroid tissue during embryologic development, which can include areas along the carotid sheath. Thus, checking this area is critical before deciding on further surgical interventions or explorations.

Exploratory maneuvers should prioritize areas where ectopic parathyroid glands are likely, and once all accessible regions are examined, other surgical steps can be taken based on findings. Therefore, attention to the carotid sheath aligns with the surgical principles of identifying all potential sources of parathyroid tissue in cases of hyperplasia.