Recurrent hyperparathyroidism after total parathyroidectomy due to multiple ectopic parathyroid glands in a patient...

We report the rare case of a recurrent hyperparathyroidism after total parathyreoidectomy due to multiple ectopic glands in a patient on long-term haemodialysis. In a today 47 years old man with membranoproliferative glomerulonephritis intermittent haemodialysis therapy was started in 1975. In 1982 an advanced secondary hyperparathyroidism with a parathormone (PTH) level > 500 pg/l was diagnosed; later on PTH concentration increased to 2,550 pg/ml. In 1987 total parathyroidectomy with parathyroid autograft into the left forearm was performed. After parathyroidectomy the PTH level fell to 150 pg/ml. In 1993 PTH concentration increased again to 1,750 pg/ml. There was no evidence for recurrent parathyroid glands in the neck or forearm. Therefore, we investigated the substernal region by 99mTc-tetrofosmin scintigraphy and magnetic resonance imaging. Both investigations showed evidence for two ectopic parathyroid glands in the anterior mediastinum. In June 1999 in an open thoracic surgical procedure only the greater parathyroid gland in the anterior mediastinum was isolated, but a second gland was detected in the posterior mediastinum. Both parathyroid glands were resected (histologically hyperplastic parathyroid gland tissue). After surgery the PTH level decreased to 340 pg/ml, but later on PTH increased again to > 1,000 pg/ml in January 2001. A control 99mTc-tetrofosmin scan showed evidence for a third ectopic parathyroid gland in the anterior mediastinum. Recurrent secondary hyperparathyroidism can rarely be caused by recurrent ectopic parathyroid glands in the mediastinum.