Diagnostic localization of ectopic parathyroid lesions: developmental consideration

Abstract

Parathyroid glands arise from the third and fourth pharyngeal pouches. Parathyroid lesions sometimes develop ectopically. The aim of this article is to illustrate the knowledge of pharyngeal apparatus development to assist with diagnostic localization of ectopic parathyroid lesions. We retrospectively reviewed charts of 23 patients who received a diagnosis of ectopic parathyroid lesions. The ectopic lesions were widely distributed; cranially lesions were located on the carotid bifurcation, caudally in the right paraaortic region, ventrally on the surface of the sternohyoid muscle, and dorsally in the paraesophageal region. In most cases, parathyroid tissues were associated with structures related to the third or fourth pharyngeal pouches that traveled to regions where the ectopic lesions ultimately developed. In a few cases, lesions were not associated with these pouches and might have developed from parathyroid tissue that migrated due to an anomalous pathway of parathyroid travel. When patients present without entopic lesions, the presence of ectopic lesions should be evaluated based on an understanding of the developmental mechanisms of parathyroid glands and the frequency with which ectopic lesions have been found in specific locations. Systematic diagnosis can minimize the frequency with which ectopic lesions are missed during clinical care and maximize their accurate localization.

An Endotracheal Ectopic Parathyroid Adenoma Mimicking Asthma

“…tracheoesophageal groove (27e33% of cases) [3]. Other ectopic sites include the inner aspect of the thyroid, neighboring region of the para-aortic arch, anterior aspect of the sternocleidomastoideus muscle, neighboring region of the hypoglossal nerve, paraesophageal region, anterior mediastinum, aortopulmonary window, and pericardium [5].…”

“…The parathyroid (PT) glands generally lie close to the posterior surface of the thyroid lobes, and there are usually four PT glands in humans [2]. Ectopic PT glands can be seen from the front of the bifurcation of the carotid artery to the pericardium because of the long path of migration of the thymus during the embryological period [3]. In this case report, we present a case involving an ectopic PT adenoma (EPA) obstructing the tracheal lumen and located in the distal part of the trachea.…”

Persistent primary hyperparathyroidism: an uncommon location for an ectopic gland - Case report and review

“…Considering inferior glands, the ectopic sites would be intrathymic, anterosuperior mediastinum, intrathyroidal, thyrothymic ligament, and submandibular area. Rarely, ectopic parathyroid glands may be located at the aortopulmonary window, pericardium, hypopharynx (pyriform sinus), nasopharynx, vagus nerve sheath (arising from the fourth pharyngeal arch, near the third and fourth pharyngeal pouches) or posterior cervical triangle (2,5,10,12,13,29,30).…”

“…In cases of early individualization of superior parathyroid glands (before the mentioned structures became completely distinct), some parathyroid cells might remain on what will become the APW. When the inferior parathyroid gland individualizes from the third pharyngeal pouch, some parathyroid cells may persist connected to the adjacent pericardium (if so, the abnormal parathyroid at APW will present some thymic tissue associated to it) (13,29,30). …”

MR appearance of parathyroid adenomas at 3 T in patients with primary hyperparathyroidism: what radiologists need to know for pre-operative localization

“…More recently, several authors proposed more expansive criteria for surgical therapy, excluding only those patients who are not able to tolerate surgery [6,7]. Nevertheless, with the variable number and anatomic location of parathyroid glands, preoperative imaging has rarely been used for traditional open-neck surgery [8][9][10][11]. Since 90 % of patients with PHPT have a single gland adenoma, minimally invasive parathyroidectomy (MIP) was introduced [12][13][14], with decreased intraoperative time, size of surgical incision and complication rates [15,16].…”