Impact of Histological Subtypes on Preoperative Localization of Parathyroid Adenomas

Introduction: Parathyroid scintigraphy and ultrasonography are the primary imaging methods used for localizing parathyroid adenomas. However, there remains a risk of missed or failed localization. This study aims to investigate the relationship between clinical and pathological findings in patients with parathyroid adenoma, focusing on the causes behind missed adenomas and localization failures. Patients and Methods: We analyzed the demographic, clinical, laboratory, and radiological data of patients who underwent surgery for primary hyperparathyroidism due to adenomas. Additionally, we reassessed the adenomas' pathologic characteristics, including size, weight, dominant cell type, and the percentage of oxyphilic cells. Results: A total of 115 patients were studied, with dominant cell types distributed as follows: 83 (71.6%) conventional chief cells, 15 (12.9%) water-clear cells, and 17 (14.7%) oxyphilic cells. The average percentage of oxyphilic cells was 21.15%. The localization rate via ultrasonography was significantly lower in the water-clear cell group (p < 0.05). While not statistically significant, the localization success using scintigraphy was lower in the oxyphilic cell group compared to others (58.8% vs. 80.7% and 86.7%). Our findings suggest that histological subtypes of parathyroid adenomas, particularly dominant cell content, may affect preoperative localization success. Conclusion: Missed parathyroid adenomas may be attributed to their histological subtypes and dominant cell composition. These factors could influence the accuracy of preoperative localization with ultrasonography and scintigraphy.