Do Biochemical Markers Reflect Parathyroid Adenoma Volume in Primary Hyperparathyroidism?

The relationship between biochemical severity parameters and adenoma burden in primary hyperparathyroidism (PHPT) has been widely studied, although some variability across studies persists. This relationship is clinically relevant for improving disease assessment and guiding surgical decision-making. This study aimed to investigate the association between preoperative biochemical parameters and both ultrasonographic and histopathological adenoma volume. A total of 526 patients with histopathologically confirmed solitary parathyroid adenoma who underwent surgery between January 2017 and December 2024 were retrospectively analyzed. Preoperative corrected serum calcium, parathyroid hormone (PTH), 25-OH vitamin D, phosphorus, albumin, and alkaline phosphatase (ALP) levels were recorded. Adenoma volume was calculated using ultrasonographic measurements and histopathological dimensions, and correlations were evaluated with appropriate statistical methods. Corrected serum calcium showed a significant positive correlation with histopathological adenoma volume (r = 0.249, p < 0.001; ρ = 0.340, p < 0.001), while its relationship with ultrasonographic volume was weaker. Ultrasonographic and histopathological volumes were strongly correlated (r = 0.68, p < 0.001). Vitamin D demonstrated a significant negative correlation with both volume measurements. PTH showed no significant association with either ultrasonographic or histopathological adenoma volume. No significant associations were found for phosphorus or albumin, and ALP showed weak correlations. Corrected serum calcium was associated with adenoma volume, particularly when assessed histopathologically, suggesting that serum calcium may partially reflect adenoma burden in PHPT, although the observed associations were modest.