Expression of cyclin D1 in parathyroid carcinomas, adenomas, and hyperplasias: A paraffin immunohistochemical study

In this study, we assessed the frequency of cyclin DI protein expression in normal and neoplastic parathyroid tissue (10 parathyroid carcinomas, 28 ad enomas, 18 hyperplasias, and 32 normal parathyroid glands) with use of a mo noclonal anticyclin D1 antibody and a heat-induced epitope retrieval method . Overexpression of cyclin D1 was identified in 10 (91%) of 11 biopsy speci mens from 10 patients with parathyroid carcinomas and in 11 (39%) of 28 par athyroid adenomas, In addition, 11 (61%) of 18 cases of parathyroid hyperpl asia also expressed cyclin DI protein, an observation not reported previous ly. These results confirm the high frequency of cyclin DI expression in par athyroid carcinomas and adenomas, In addition, the results of this study in dicate that overexpression of cyclin D1 protein is not limited to neoplasti c proliferations of parathyroid tissue but is also seen in non-neoplastic p roliferations of parathyroid gland Cyclin D1 protein expression was rarely (<6%) present in normal parathyroid tissue.