We report here a dialysis patient with
secondary hyperparathyroidism who had a history of
parathyroidectomy for
primary hyperparathyroidism 27 years previously. The patient was a 48-year-old male. In 1974, he was diagnosed as having
primary hyperparathyroidism and an
adenoma was completely resected in the Department of Urology, Osaka University Hospital. In 1997, he started
hemodialysis for
chronic renal failure by
diabetic nephropathy. Since his intact-PTH was high, we started intravenous
vitamin-D pulse
therapy, but intact-PTH did not decrease. We could not detect any parathyroid glands by ultrasonography and 201TlCl-99mTcO4-scintigraphy around the thyroid gland. Finally, chest-CT and 99mTc-MIBI scintigraphy revealed a ectopic parathyroid gland in the mediastine, and the ectopic parathyroid gland was successfully resected in July, 2001. In order to distinguish whether the resected ectopic parathyroid gland was due to primary
adenoma or secondary
hyperplasia, we used an immunohistochemical technique to examine the expression of PRAD1/
cyclin D1, Ki67, and p27 and sequence analysis of the MEN1 gene. As a result, the labeling index (LI) of PRAD1/
cyclin D1 was 4, LI of Ki67 was 36, and LI of p27 was 257. Moreover, germline-mutation and somatic-mutation of MEN1 gene was not detected. These findings suggested that the resected parathyroid gland was a nodular
hyperplasia of
secondary hyperparathyroidism. In conclusion, immunohistochemical findings of parathyroid tissue and sequence analysis of MEN1 gene could be useful for the differential diagnosis of primary
adenoma and secondary
hyperplasia.