Primary hyperparathyroidism (pHPT) is often accompanied by thyroid diseases, which may be confusing in understanding preoperative parathyroid disease conditions and thereby complicate the intraoperative decision-making process. In this review, we aimed to provide an updated overview of the coincidence of these disorders. We conducted a PubMed search for articles using the following key words: primary hyperparathyroidism, thyroid disease, nodular hyperplasia, papillary carcinoma, Graves’ disease, and thyroiditis. Articles were obtained and reviewed to analyze the coexistence of primary hyperparathyroidism and thyroid diseases. The findings of coexisting thyroid disease in patients with primary hyperparathyroidism were reported in the range of 22% to 70%, including nodular hyperplasia, papillary carcinoma, Hashimoto’s thyroiditis, Hurtle’s adenoma, medullary carcinoma, and Graves’ disease. Several hypotheses have been presented to understand mechanisms that link thyroid disease to pHPT, but no firm conclusions currently exist regarding the etiologic relationship between these 2 disorders. Ultrasonography (US) and 99m-Technetium-Methoxy-isobutylisonitril (99mTc-MIBI) scintigraphy are essential in the evaluation of these patients, which can be helpful to modify the planned procedure. A definitive one-step surgery to treat both pathologies allows patients to avoid the risks associated with re-operative neck surgery and associated morbidity. Attention should be paid to the possible coincidence of thyroid and parathyroid diseases, thus leading to safer and more efficient management of these patients.

Keywords: Carcinoma, Papillary, Focal nodular hyperplasia, Hyperparathyroidism, Primary, Thyroid Diseases