Archive | 2019
A Patient with Papillary Thyroid Carcinoma and Biochemical Incomplete Response with Gradually Increasing Tg Values and Negative Imaging Studies
Abstract
A 61-year-old asymptomatic female patient having no risk factors for thyroid carcinoma underwent neck ultrasound. Following a diagnosis of papillary thyroid cancer (PTC) by fine needle aspiration biopsy, the patient underwent total thyroidectomy and right lateral neck lymph node dissection. Histopathological examination of the surgical specimen revealed two PTC foci in the right thyroidal lobe that were 4 cm and 0.1 cm in diameter. The patient received radioiodine ablation treatment (RAT) with 5550 MBq (150 mCi) iodine-131 (I-131) 3 months after the operation. Six months after RAT, diagnostic whole-body scintigraphy was performed with endogenous TSH stimulation with 185 MBq I-131. Serum TSH-stimulated Tg levels were 66.55 ng/mL, and I-131 scintigraphy revealed the absence of any pathological uptake. Neck ultrasound (US) and computed tomography (CT) of the thorax were normal. A 18F-FDG PET/BT was planned to search for possible recurrent disease, but it was determined normal. Serum thyroglobulin levels gradually increased to 89.79 ng/mL during the 8-year follow-up period. Several neck USGs, thorax CTs, and one additional 18F-FDG PET/CT were performed. Finally, cranial CT and Tc-99m MDP bone scintigraphy were performed. No residual or metastatic tissue detected so far.