Parathyroid adenoma: a comprehensive biochemical and histological correlative study.

ABSTRACT

OBJECTIVE: To investigate the controversial relationship between preoperative calcium and parathyroid hormone levels and the dimensions and histological features of parathyroid adenoma in patients with primary hyperparathyroidism. STUDY DESIGN: Historical cohort. SETTING: Tertiary medical centre. SUBJECTS AND METHODS: Clinical and tumour-related data were collected from the medical files of all patients who underwent parathyroidectomy for primary hyperparathyroidism in 1996-2012. Preoperative blood parathyroid hormone and calcium levels and urine calcium levels were correlated with the size, weight and volume of the parathyroid adenoma. Pathohistological features were determined in a representative sample of archived paraffin-embedded sections and analysed by calcium or parathyroid hormone level (high/low) and adenoma weight (high/low). RESULTS: A total of 378 patients were included. There was a statistically significant direct correlation of preoperative calcium and parathyroid hormone levels with tumour dimensions and of tumour weight and chief-cell percentage. At a preoperative calcium level >11.5 mg/dL and parathyroid hormone (PTH) level >165 mg/dL, we predict that the adenoma would measure more than 2.7 g, 2.18 cm and volume of 3.59 cm3 . CONCLUSIONS: In patients with primary hyperparathyroidism, preoperative calcium and PTH levels may be predictive of parathyroid adenoma dimensions.