A case of ectopic parathyroid gland hyperplasia in the pyriform sinus.

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.