Primary hyperparathyroidism due to an intrathyroidal parathyroid adenoma associated with chronic lymphocytic thyroiditis.

This is a case of a 44-year-old woman with an anterior neck mass and hypothyroidism who presented with an incidental finding of an elevated serum calcium level and was found to have primary hyperparathyroidism and osteoporosis. During surgical exploration no parathyroid adenoma was found, although a nodule was palpated within the right thyroid lobe. Examination of the excised right thyroid lobe revealed an intrathyroidal parathyroid adenoma and chronic lymphocytic thyroiditis. After surgery, she did not develop severe hypocalcaemia and this was attributed to preoperative treatment with pamidronate. In the months following surgery, parathyroid hormone remained undetectable.