Benign Parathyroid Gland Tumors and their Heterogeneity

Background: Primary hyperparathyroidism (pHPT) can be caused by different pathologic lesions – benign and malignant. The frequencies of changes vary, mainly because different criteria for diagnosis. It is especially visible in the group of benign lesions, which as it turns out, are not uniform in nature. The aim of the study was to attempt to assess the heterogeneity of benign parathyroid lesions, both adenoma and hyperplasia.\r\n\r\nMethods: Resected benign lesions from consecutive series of 125 patients treated surgically for pHPT, were studied retrospectively. We were looking for a corelation between DNA ploidy, cell proliferation activity (S phase fraction) and the expression of parafibromin and galectin-3.\r\n\r\nResults: In 74 (59.2%) of patients the diagnosis according to histopathological evaluation was benign adenoma and in 51 (40.8%) parathyroid hyperplasia. Diploid pathologies were found in 72 (57.6%) cases and aneuploid in 53(42.4%). From 74 adenomas, 39 (55%) were considered diploid and 35 (45%) aneuploid. Positive parafibromin expression was observed in 26 (49%) of aneuploid tumors and in 39 (54%) of diploid. Galectin-3 expression was found in 25 (47%) aneuploid and 30 (41%) diploid. In this changes of parathyroid glands, we did not observe any important differences between ploidy of cells and expression of parafibromin (p=0.16) and galectin (p- 0.39). Weak, but important correlation was observed between parafibromin expression and number of cells in S phase fraction in diploid pathologies (p=0.047). There is important, but weak correlation between galectin-3 expression and amount of cells in S phase fraction in aneuploid pathologies (p=0.05). In diploid pathologies, the correlation was not observed (R=0.02, p=0.83).\r\n\r\nConclusions: 1) The nature of the cellular ploidy of benign parathyroid lesions indicates the heterogeneity. 2) A negative reactions with parafibromin and positive reactions with galectin-3 were found among adenomas as well as benign parathyroid hyperplasia. 3) In benign parathyroid lesions the expression of parafibromin and galectin-3 correlate with an increase in the number of S phase fraction cells, diploid and aneuploid, respectively.