Interesting ImagesParathyroid Carcinoma With Marked Uptake of 99mTcO4−Pirayesh, Elahe MD; Tavakoli, Mehrdad MDAuthor Information From the Department of Nuclear Medicine, Shohada-e-Tajrish Medical Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Received for publication July 27, 2020; revision accepted October 22, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Elahe Pirayesh, MD, Department of Nuclear Medicine, Shohada-e-Tajrish Medical Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Shahrdari Street, 1989934148 Tajrish Sq, Tehran, Iran. E-mail: [email protected]. Clinical Nuclear Medicine: February 2021 - Volume 46 - Issue 2 - p 151-152 doi: 10.1097/RLU.0000000000003448 Buy Metrics Abstract A 51-year-old man with a palpable neck mass and elevated parathyroid hormone was referred to our department for parathyroid scintigraphy. After injection of 740 MBq 99mTc-MIBI, a dual-phase scan was obtained, which revealed a persistent and intense focal hyperactivity in the left side of the neck (compatible with the neck mass). Thyroid scan with 99mTcO4− also showed increased uptake of the mass, similar to a hot thyroid nodule. After surgery, parathyroid carcinoma was confirmed pathologically. This case demonstrates a rare presentation of parathyroid carcinoma as a hot nodule in thyroid scan, which has been attributed to hypervascularity of the lesion. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.