ABSTRACT
Medullary thyroid carcinoma (MTC) is a rare and challenging malignancy. In patients with residual MTC, the tumor detection rate is generally low for most of the currently available imaging techniques. Various imaging methods have already been used for the detection of residual tumor, but no modality has been shown to be superior to others. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has recently been proposed to identify residual MTC, but this procedure also has limitations as small masses are rarely detected. So, a multimodality imaging approach is recommended for detecting residual MTC. We report here on a case of residual MTC that was detected by 18F-FDG PET/CT in a patient with persistent hypercalcitoninemia after total thyroidectomy and bilateral lymph node dissection.