Two cases of mediastinal parathyroid cyst

Abstract

Two cases of mediastinal parathyroid cyst were described. Case 1.-A 32-year-old woman was admitted to our hospital for a right upper mediastinal shadow on the chest X ray film. The serum calcium level was high on her admission. A CT scan of the chest revealed a homogenous water density mass in the superior mediastinum. As a thymic cyst was suspected, the cyst was removed through a median sternotomy, together with the thymus. It was connected with the thymus, but there was no connection with the thyroid gland. Histological diagnosis was the cystic degeneration of the aberrant parathyroid adenoma of the thymus. Both serum calcium and PTH levels after operation returned to normal limits. It was considered a functional aberrant parathyroid cyst. Case 2.-A 62-year-old woman complained of facial edema. As the cyst was palpable at the lower anterior neck, a percutaneous cyst aspiration by a fine needle was performed. As PTH level in the content fluid was high, we could diagnose this case as parathyroid cyst preoperatively. The cyst was removed by transcervical approach and the parathyroid gland was histologically recognized in the cyst wall. It was considered a nonfunctional parathyroid cyst.