Table 2.

The number and locations of the parathyroid glands.

Number of parathyroid glands	Number of patients	Number of upper and lower parathyroid glands (ectopic parathyroid glands)	Number of supernumerary parathyroid glands
	177	703 (90, comprising 87 intrathymic, 2 intrathyroid, and 1 mediastinal glands)	44, comprising 6 left lower, 2 right lower, 1 carotid sheath, and 35 intrathymic glands
3	5	15 (0)	0
4	133	532 (64, comprising 2 intrathyroid, 1 mediastinal, and 61 intrathymic glands)	0
5	34	136 (22 intrathymic glands)	34, comprising 4 left lower, 2 right lower, and 28 intrathymic glands
6	5	20 (4 intrathymic glands)	10, comprising 1 carotid sheath, 2 left lower, and 7 intrathymic glands