TITLE:
Evidence-Based Approach to a “Missing” Parathyroid Gland during Thyroid or Parathyroid Surgery
AUTHORS:
Rodrigo Arrangoiz, Fernando Cordera, Mateo Zambrano
KEYWORDS:
Parathyroid Gland, Ectopic Parathyroid Gland, Missing Parathyroid Gland, Parathyroid Embryology, Thyroidectomy, Parathyroidectomy, Mediastinal Parathyroid Gland, Intrathyroidal Parathyroid Gland, Perrier Classification, Surgical Anatomy, Parathyroid Localization
JOURNAL NAME:
International Journal of Otolaryngology and Head & Neck Surgery,
Vol.15 No.4,
July
9,
2026
ABSTRACT: Failure to identify a parathyroid gland during thyroidectomy or parathyroidectomy represents a well-recognized intraoperative challenge and is most commonly explained by ectopic gland location rather than true agenesis. A comprehensive understanding of parathyroid embryology, migration patterns, and cervical anatomy is therefore essential for safe endocrine neck surgery and for minimizing failed explorations, hypoparathyroidism, and recurrent disease. This review provides a practical and surgically oriented overview of the “missing” parathyroid gland, integrating embryologic development, anatomic variability, operative identification strategies, and contemporary nomenclature systems. The embryologic descent of the superior and inferior parathyroid glands from the fourth and third pharyngeal pouches, respectively, explains the predictable distribution of ectopic glands encountered during surgery. Superior glands typically maintain relatively constant locations near the posterior aspect of the upper thyroid pole, whereas inferior glands demonstrate greater positional variability because of their longer migratory course with the thymus. Common ectopic locations include the tracheoesophageal groove, retroesophageal space, thyrothymic ligament, cervical thymus, carotid sheath, retropharyngeal region, mediastinum, and intrathyroidal or subcapsular locations. This review emphasizes operative pearls for gland identification, including recognition of key landmarks such as the inferior thyroid artery, recurrent laryngeal nerve, prevertebral fascia, cervical thymus, and characteristic parathyroid fat pads. Strategies for systematic exploration are discussed in the context of both thyroidectomy and parathyroidectomy. Additionally, the manuscript reviews the Perrier classification system for ectopic parathyroid glands and proposes its practical application during cervical exploration to facilitate structured localization of missing glands. By combining embryologic principles with operative anatomy and contemporary surgical nomenclature, this review aims to provide endocrine surgeons, trainees, and head and neck surgeons with a clinically relevant framework for identifying orthotopic and ectopic parathyroid glands, reducing operative failure, and improving surgical outcomes in thyroid and parathyroid surgery.