Toxic nodular goiter was diagnosed on the basis of having
hot nodule on thyroid scan with low TSH and high FT4/T4.
Hyperfunctional nodule on radionuclide imaging is believed to exclude malignancy, but malignancy is occasionally seen co-existing with homogenous
hot nodule. Thus, the main limitation of radionuclide scanning, regardless of isotope used is that it will not differentiate benign and malignant nodules
On scintigraphy, the gland demonstrated increased uptake of technetium-99m pertechnetate and a discrete
hot nodule in the upper pole of the right lobe corresponding to the nodule detected on ultrasound (Figure 1(b)).
(8) If thyroid nodules are detected on ultrasound scan, the patient should undergo thyroid scintiscan to establish the presence of
hot nodules. If a patient has a parathyroid adenoma and a
hot nodule, the therapy of choice is combined resection of the parathyroid adenoma plus resection of the nodule.
Cells with activating mutation may have an increased expression of the NIS, which is seen as a high uptake or '
hot nodule' image on scintigraphy (10).
A
hot nodule is almost always benign however a cold nodule requires further diagnostic evaluation.
If the scan shows a
hot nodule, clinical follow-up with repeat FNA biopsy in 3 to 6 months is appropriate.
Comparison of initial findings with final surgical pathology (n [%]) in 243 patients who underwent diagnostic scintigraphy Final surgical pathology Initial finding Malignant Benign Cold nodule (n = 189) 52 (27.5) 137 (72.5)
Hot nodule (n = 35) 2 (5.7) 33 (94.3) Goiter (n = 9) 1 (11.1) 8 (88.9) Normal (n = 10) 2 (20.0) 8 (80.0) Total (n = 243) 57 (23.5) 186 (76.5) Table 3.
Age, y/Sex Radiologic Findings 1 12/F Ultrasound revealed com- plex cystic 4 x 3.5-cm nodule; thyroid scan showed
hot nodule with cold areas 2 15/F Warm nodule noted on thyroid scan 3 11/M Not performed Case No.
Thyroid ultrasound showed a large nodule in the right lobe of the thyroid gland, and thyroid scan showed a
hot nodule. After excluding right ventricular failure, biliary obstruction, superin fection, and hepatocellular carcinoma, the marked cholestatic jaundice was thought to be caused by thyrotoxicosis.
Patients having a hyperfunctioning or
hot nodule were excluded from the study.
(5) 2017 Ultrasound: Multiple solid nodules in both lobes TT Present patient Ultrasound and nuclear scan: Multiple solid and
hot nodules in both lobes TT MNG: multinodular goiter; TT: total thyroidectomy
