Thyroid pathologies accompanying primary hyperparathyroidism: a high rate of papillary thyroid microcarcinoma.

OBJECTIVE Thyroid pathologies and non-medullary thyroid cancer often accompany primary hyperparathyroidism (PHPT). The purpose of this study was to examine the association between thyroid diseases, especially micropapillary thyroid cancer, with PHPT. MATERIAL AND METHODS Data regarding 46 patients who were operated on with a diagnosis of PHPT at Inonu University Faculty of Medicine, General Surgery Clinic between June 2009 and March 2013 were retrospectively analyzed. Age, gender, levels of preoperative calcium, parathyroid hormone and phosphorus, and the histopathological results of the removed parathyroid and thyroid tissues were evaluated. All of the patients had a preoperative diagnosis of PHPT and there was no history of radiation to the head and neck region in any of the patients. RESULTS Out of the 46 patients who were operated on for PHPT, 39 were female and 7 were male. The mean age was 52.8 years (25-76). Simultaneous thyroidectomy was performed in 35 patients (76.1%) due to an accompanying thyroid disorder. Papillary microcarcinoma was detected in 5 of these 35 (10.9%) patients who underwent thyroidectomy, two of which (40%) were multifocal tumors. The benign thyroid pathologies detected in the remaining 30 (65.2%) cases included lymphocytic thyroiditis in 3, Hashimoto thyroiditis in 1, follicular adenoma in 3 (two of which was Hurtle cell), and nodular colloidal goiter in 23 patients. The preoperative serum phosphate level was significantly higher in the group with papillary thyroid microcarcinoma (p=0.013). CONCLUSION In regions where goiter is endemic, thyroid diseases and thyroid papillary microcarcinoma occur in association with PHPT at a higher rate compared to the normal population. Therefore, we believe that patients who are planned for surgery due to PHPT should be thoroughly investigated for the presence of any concomitant malignant thyroid pathologies in the preoperative period. It should also be kept in mind that patients with high blood serum phosphate values may have an increased risk of papillary thyroid microcarcinoma.