PET using the radiotracer 18F-fluorodeoxyglucose (FDG) was performed in a patient who presented with elevated thyroglobulin (Tg) levels several years after initial therapy of follicular thyroid carcinoma (oncocytic variant) and in whom high-dose radioiodine (131I) failed to locate recurrent tumor or to decrease Tg levels. A focal fluorodeoxyglucose uptake in the apical septum of the heart did not have a discernible correlate in echocardiography or MRI for more than 12 months. Finally, a metastasis of the follicular thyroid carcinoma with partly squamous cell differentiation was confirmed and treated by resection and stereotactic body radiotherapy.
From the Departments of *Nuclear Medicine,
‡Pathology, University Hospital Münster, Münster, Germany.
Received for publication July 4, 2018; revision accepted August 23, 2018.
Conflicts of interest and sources of funding: none declared.
Correspondence to: Lars Stegger, MD, PhD, Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany. E-mail: firstname.lastname@example.org.