A case of parathyroid adenoma adjacent to the thoracic spine in a hemodialysis patient

Ectopic parathyroid glands are detected occasionally, especially in cases of recurrent hyperparathyroidism after initial parathyroidectomy. Their ectopic locations usually result from faulty migration during embryogenesis. Ectopic parathyroid glands can be found within the thyroid gland, thymus, mediastinum, carotid sheath, or retropharynx, which lie along the path of their normal migration. Here we report a rare case of parathyroid adenoma adjacent to the thoracic spine in a hemodialysis patient who had undergone parathyroidectomy previously. A 67-year-old woman on maintenance hemodialysis since 1993 developed hyperparathyroidism. She underwent total parathyroidectomy with autotransplantation in 2007. Histological examination of the parathyroid glands showed hyperplasia in three glands and adenoma in one. Serum parathyroid hormone levels gradually increased after a year. Ultrasonography of the neck and upper limbs was negative, but technetium-99-sestamibi scanning showed focal uptake in the posterior mediastinum. Computed tomography and magnetic resonance imaging confirmed a tumor adjacent to the left costovertebral junction of the third thoracic vertebra. A tumor resection was performed in 2010, and histopathological examination showed a parathyroid adenoma. Parathyroid adenoma adjacent to the thoracic spine has not been reported previously, and our case suggests that technetium-9-sestamibi scanning is useful for the correct preoperative diagnosis of such rare cases of ectopic parathyroid glands.