[Ectopic mediastinal parathyroid adenoma].

We experienced 3 surgical cases with ectopic mediastinal parathyroid adenoma. All patients checked elevated serum calcium levels and parathyroid hormone levels above normal range so we diagnosed their illness as primary hyperparathyroidism. Two had treated urinary tract lithiasis for long time, and the other had no symptoms by hypercalcemia. To determine the location of abnormal parathyroid glands, 99mTc-methoxy-isobutyl-isonitrile (MIBI) scintigraphy, chest computed tomography (CT) scan and/or magnetic resonance imaging (MRI) were done, then posterior and anterior mediastinal tumors were revealed. Especially MIBI scintigraphy was very useful as diagnostic procedure for small ectopic parathyroid adenoma. It's considered that large tumor in the posterior mediastinum like case 1 is originated from upper parathyroid gland, and small tumor in the anterior mediastinum like case 2, 3 is originated from lower parathyroid gland. Tumors were resected via small thoracotomy with thoracoscope, cervical incision and partial median sternotomy respectively. Serum calcium and parathyroid hormone levels were normalized immediately. If we can detect the accurate location of small ectopic parathyroid adenoma using some intraoperative method, the tumor is resected by less invasive procedure.