A 34 year-old man presented with hyperparathyroidism manifested by a history of kidney stones, hypercalcemia and elevated serum parathyroid hormone levels, of 2 - 3 years' duration. As expected, after 10 minutes the Technetium 99m-Sestamibiscan showed uptake in the thyroid gland. However, after 3 hours, the uptake washed off from the thyroid without identifying a parathyroid adenoma. In addition, there was shortness of breath on exertion.
A CT scan of the neck revealed a large cystic mass inferior to the left thyroid lobe, extending inferiorly into the mediastinum, compressing and displacing the trachea to the right side.
This mass appeared well encapsulated and exhibited calcium deposits in the capsule.
At surgery, there was a well encapsulated mass extending below the left thyroid lobe into the mediastinum. The capsule was tough and contained calcium that crackled under the fingers like an egg shell.
On frozen section, the mass consisted of a well encapsulated cyst with flattened parathyroid tissue in its walls.
This diagram shows the cyst behind the left clavicle. Note the tracheal displacement and compression.
The photograph on the left shows the parathyroid cyst being "delivered" through a thyroidectomy incision. The cyst measured 3.5 x 4 x 7 cm. The left superior parathyroid was also noted to be enlarged. It was taken out too.
As soon as the specimen was removed, the intraoperative serum calcium and parathyroid hormone levels dropped to normal.