Location, number and morphology of parathyroid glands: results from a large anatomical series.

Surgical management of parathyroid gland disease may sometimes be difficult, due mainly to the surgeon's failure to successfully detect parathyroids in unusual locations. The records of 942 cadavers (574 men and 368 women) who underwent autopsy in the Department of Forensic Medicine in Athens during the period 1988-2009 were reviewed. In total, 3,796 parathyroid glands were resected and histologically verified. Parathyroid glands varied in number. In 47 cases (5 %), one supernumerary (fifth) parathyroid was found, while in 19 cases (2 %) three parathyroid glands found. Superior glands were larger than inferior ones. However, there was no significant difference between the genders with respect to gland size. In 324 (8.5 %) out of 3,796, the glands were detected in an ectopic location: 7 (0.2 %) in the thyroid parenchyma, 79 (2 %) in different sites in the neck and 238 (6.3 %) in the mediastinum, 152 (4.1 %) of which were found in the upper and 86 (2.2 %) in the lower mediastinum. Significant anatomical variations of normal parathyroid glands may exist regarding number and location-knowledge that is essential for their successful identification and surgical management.