Interesting ImagesHyperestrogenism on 18F-FDG PET/CT in a Patient With Estrogen-Producing Ovarian Clear Cell CarcinomaKoyasu, Sho MD, PhD∗; Otani, Tomoaki MD∗; Minamiguchi, Sachiko MD, PhD†; Nakamoto, Yuji MD, PhD∗; Togashi, Kaori MD, PhD∗Author Information From the Departments of ∗Diagnostic Imaging and Nuclear Medicine †Diagnostic Pathology, Graduate School of Medicine, Kyoto University, Kyoto City, Japan. Received for publication November 30, 2019; revision accepted February 3, 2020. Conflicts of interest and sources of funding: none declared. The present study was financially supported by JSPS KAKENHI (grant number 19K17164). Correspondence to: Sho Koyasu, MD, PhD, Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto City, 606-8507, Japan. E-mail: email@example.com. Clinical Nuclear Medicine: July 2020 - Volume 45 - Issue 7 - p e320-e322 doi: 10.1097/RLU.0000000000003009 Buy Metrics Abstract A 78-year-old woman was referred to the gynecologic outpatient department because she was suspected of having ovarian cancer based on an imaging study performed during a general medical examination. Further examination using 18F-FDG PET/CT revealed a bulky mass lesion with low FDG avidity, as well as surprisingly strong bilateral breast radiotracer uptake despite the patient's age. Thus, an estrogen-producing tumor was suspected. Bilateral salpingo-oophorectomy was performed, and surgical pathology diagnosed the tumor as clear cell carcinoma of the ovary. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.