[Mechanism of parathyroid cell proliferation in primary hyperparathyroidism]

In primary hyperparathyroidism molecular biology techniques applied to the pathological parathyroid tissue have shown that cell proliferation is monoclonal in many sporadic adenomas and in the largest parathyroid glands of multiple endocrine neoplasia type 1 (MEN-1). On the other hand, monoclonality has not been found in sporadic hyperplasia and in the smaller parathyroid glands of MEN-1. In addition, abnormalities have been observed in chromosome 11 which contains the parathyroid hormone (PTH) gene and the MEN-1 associated gene. The PTH gene was rearranged in sporadic adenomas, and there was a varying degree of chromosome 11 allele delection in sporadic adenomas and in MEN-1. The relationship between these abnormalities and parathyroid cell proliferation is controverted, and further studies are required to determine their exact role in the development of primary hyperparathyroidism.