In contrast, preoperatively determined parathyroid hormone correlated moderately with adenoma weight (r = 0.44; p < 0.001) and adenoma volume (r = 0.17, p = 0.024), whereas calcium showed only weak, albeit significant, correlations with adenoma weight (r = 0.20; p = 0.005) and volume (r = 0.17; p = 0.024). This evidence concerns the gene PTH and adenoma.