Early parathyroid MIBI SPECT imaging in the diagnosis of persistent hyperparathyroidism

We present a case that demonstrates the utility of early SPECT images associated with fusion images with MRI for presurgical localization in a case of persistent hyperparathyroidism after a first surgery. Three years after that surgery, severe hypercalcemia (14.7 mg/dL) and elevated parathormone (PTH) (944 pg/mL) were detected. MRI and SPECT parathyroid scintigraphy showed an abnormal parathyroid lesion localized behind the inferior pole of the thyroid right lobe. At surgical reexploration a right inferior parathyroid adenoma was removed (258 mg). However, intraoperative PTH remained high and a total thyroidectomy was performed looking for an intrathyroid lesion. After that, the elevated PTH persisted and an ectopic parathyroid gland was identified in the tracheoesophageal groove (958 mg), corresponding with the lesion seen on the fusion image of MRI and SPECT. After removal of this lesion, the PTH dropped to 85%.