Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 7 1 2022 06 14 21 24 Reza Hajebi Department of Surgery, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. Elham Nazar Department of Pathology, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. Shabnam Mashhadi Department of Pathology, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2021 03 06 2021 04 10 Thyroid malignant neoplasms are the most prevalent cancer of the endocrine system, and their concurrence with parathyroid neoplasms is extremely rare. We report a 69-year-old woman presenting with hypercalcemia and thyroid nodule, which histologic examination revealed bilateral papillary thyroid carcinoma with different variants coincident with parathyroid adenoma. Awareness of concomitant parathyroid and thyroid diseases may help manage patients with hypercalcemia history. So, we recommended a preoperative calcium check in a patient with a thyroid nodule. https://crcp.tums.ac.ir/index.php/crcp/article/view/491