supernumerary parathyroid

Full Definition

Anatomical variants involving the presence of more than the normal four parathyroid glands, occurring in approximately 5-15% of the population. Supernumerary parathyroid glands are most commonly found as a fifth gland and can be located in various positions including the thymus, carotid sheath, or retroesophageal space. These additional glands can become hyperplastic or develop adenomas, potentially causing persistent or recurrent hyperparathyroidism if not identified and addressed during initial surgery. Recognition of this anatomical variant is crucial for successful parathyroid surgery.

Usage

Usage note: Often described by number (fifth gland) or location (thymic parathyroid).

In Context

• "Exploration revealed a supernumerary parathyroid gland in the thymus accounting for persistent hyperparathyroidism." — reoperative surgery report
• "The preoperative imaging suggested the presence of supernumerary parathyroid tissue requiring extended exploration." — surgical planning note