Value of ploidy pattern and nuclear texture in the diagnosis of primary hyperparathyroidism

To determine if there are subvisual differences (quantitation of DNA and study of chromatin texture) that distinguish single-gland parathyroid disease (adenoma) from multiple-gland disease (hyperplasia).

Forty-eight parathyroid glands from 41 patients with primary hyperparathyroidism were studied. Cytometric differences between the chief cells and clear cells were sought. An image cytometer was used to study histologic sections stained with DNA stain reagent. In each case a total of 200 cells were measured in consecutive fields. To distinguish chief cells from clear cells, a sample of 15,600 cells collected in consecutive fields in 78 histologic sections was analyzed.

The results indicated that none of the continuous variables differentiated between single-gland and multiple-gland parathyroid disease. The most common ploidy pattern was diploid (25/45), followed by hypodiploid (7/45) and polyploid (5/45). A tetraploid population > 3% was found in 18/45 of the cases and was more frequent in single-gland lesions (15/34) than in multiple-gland lesions (3/11). The most significant discrete variables were growth pattern and binucleation or multinucleation. Clear and chief cells were classified correctly in 61.3% of the crossover validation tests using the standard deviation of nuclear shape karyometric variable and in 76.3% using the standard deviation of maximal correlation coefficient karyometric variable. Although ploidy pattern did not show significant differences, polyploidy, aneuploidy and tetraploidy > 3% were slightly more common in chief cells.

In primary hyperparathyroidism there are no subvisual differences that can distinguish adenoma from hyperplasia. Nonetheless, by cytometry, most parathyroid cells can be classified correctly as clear or chief cells.