Fig. 2

Patient in long-term follow-up with unifocal locally invasive (T4aN0M0) papillary carcinoma already submitted to total thyroidectomy and radioiodine ablation. Diagnostic 131-WBS in both anterior and posterior views (a, b) and planar anterior and posterior spot views (c, d) detected a slight radioiodine-avid focus (black arrow) in neck superior middle region classified as residue. SPECT/CT in coronal view (e) confirmed this area including two foci (white arrows), and also evidenced numerous foci of elevated radioiodine uptake in the neck right lateral region (red arrows) beginning from the sub-mandibular area as far as jugulum in a vertical line along laterocervical and paratracheal regions. To these foci, lymph nodes corresponded at CT (f). Thyroglobulin levels in hypothyroidism were 211 ng/ml; anti-thyroglobulin antibodies were negative. The patient underwent a second surgery and the lymph nodes were ascertained as malignant at histology. Afterward, the patient received two further therapeutic radioiodine doses