A 57-year-old man on hemodialysis for chronic renal failure durign these 17years was admitted to the hospital because of gradually intensified symptoms of renal osteodystrophy which started 2-3years before admission. The patient underwent total removal of four parathyroid glands, a total of 600mg in weight, and autotrasplantation. Thereafter high levels of serum Ca and intact-PTH persisted, and so a^99m Tc-MIBI scintigraphy was performed with a suspicion of the presence of the fifth gland that revealed a strong accumulation in the left superior mediastinum. At the initial operation, the gland was not revealed even by ultrasonography, CT scan, ^99mTc-²⁰¹T1 subtraction scintigram. Upon reoperation, a nodular hypertrophic parathyroid gland which was 3.2×1.6×1.2cm in size and 2, 650mg in weight was detected in the same portion.
We think that ^99mTc-MIBI scintigraphy is valuable to detect parathyroid gland and/or excessive glands in case of renal hyperparathyroidism.