Variations in the anatomical position of the normal and diseased parathyroid glands

ABSTRACT

Despite the availability of expert surgeons and preoperative imaging investigations, some patients require re-operation for persistent or recurrent hyperparathyroidism. Ectopic Parathyroid Glands [PGs] are a cause for failed parathyroid exploration. To evaluate the prevalence and location of normal parathyroid glands and diseased glands taken from subjects with End-Stage Renal Disease [ESRD]. A total of 410 parathyroid glands were recovered from 116 postmortem subjects of whom 37 were diagnosed as suffering from ESRD. In the rest, the death had resulted from disease unrelated to parathyroid disorder. 155 [69.3%] of both normal left and right superior PGs were located at cricothyroid junction; 46 [29.3%] were behind the upper pole of thyroid gland; 2 [2.6%] were behind pharyngoesophageal junction. 68 [47.1%] of the normal inferior PGs were found at the lateroposterior surface of the lower pole of thyroid gland; 62 [43.7%] were within the thymic tongue and 14 [9.7%] along the carotid artery. The normal ectopic PGs were found only in 22 cases. The superior PGs were 4 [18.2%] in an extracapsular posterior position, 2 [9.1%] intrathyroidal and 1 [4.5%] retropharyngeal. The inferior ectopic PGs were 15 [68.2%] and were found within the mediastinal thymus. 19 [51.4%] of the enlarged PGs were found within the thyroid parenchyma, 8 [21.6%] within the thymic tongue, 6 [16.2%] within the thymus, 2 [5.4%] were within the carotid sheath and 1 [2.7%] in the retropharyngeal or retroesophageal position. The presence of ectopic PGs in secondary hyperparathyroidism is sufficiently important to justify their exhaustive search. As the preoperative image exams present low sensibility to locate them, it is necessary to develop an exploratory routine embracing the most common sites of location