Interesting ImagesEctopic Parathyroid Adenoma of the Piriform Sinus on Parathyroid 4D-CT and 99mTc-MIBI SPECT/CTHsieh, Meng-Chieh P. MD; Nemer, John S. MD; Beylergil, Volkan MD; Yeh, Randy MDAuthor Information From the Department of Radiology, New York Presbyterian Hospital/Columbia University Medical Center, New York, NY. Received for publication April 5, 2019; revision accepted May 7, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Meng-Chieh P. Hsieh, MD, Division of Nuclear Medicine/Department of Radiology, Columbia University Medical Center, 622 W 168th St, PB-1-301, New York, NY 10032. E-mail: email@example.com. Clinical Nuclear Medicine: August 2020 - Volume 45 - Issue 8 - p e358-e359 doi: 10.1097/RLU.0000000000003163 Buy Metrics Abstract Ectopic parathyroid adenomas are a common cause of postsurgical persistent primary hyperparathyroidism. Our case highlights a patient with a negative bilateral 4-gland exploration with follow-up parathyroid 4-dimensional CT and 99mTc-MIBI SPECT/CT, yielding focal uptake in the right piriform sinus. Subsequent direct laryngoscopy revealed a mass in the piriform sinus, which was resected with surgical pathology yielding parathyroid adenoma. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.