Variability in the location of parathyroid glands is well recognized. There are usually 4 parathyroid glands located in the area of the thyroid gland, but embryologically, they may be found anywhere from the angle of the jaw to the pericardium. We report a case of an ectopic parathyroid gland in the pyriform sinus. It appeared as a tumorous lesion in the pyriform sinus owing to progress of secondary hyperparathyroidism.
Fukumoto A, Nonaka M, Kamio T, Kamura E, Ozu C, Baba S, Ohaki Y. A Case of Ectopic Parathyroid Gland Hyperplasia in the Pyriform Sinus. Arch Otolaryngol Head Neck Surg. 2002;128(1):71-74. doi:10.1001/archotol.128.1.71