Extrathyroidal uptake from thyroid carcinoma on [99m]Tc-pertechnetate scintigraphy

ABSTRACT

Three cases of imaging with 99mTc-pertechnetate [[99m]TcO[4]] and unusual positive lymph node uptake in the neck are reported hereby. Two cases were later diagnosed to be well-differentiated thyroid carcinoma, [DTC] with nodal metastasis. The third was a confirmed case of carcinoma thyroid that had presented with mass in the neck soon after surgery, being prepared for ablative dose of radioactive iodine [131]I. All three were young females under 40 years of age. These 3 cases signify that extra thyroidal areas of uptake on a routine thyroid scan with [99m]TcO[4] can some time be due to thyroid carcinoma with regional metastases. Foci of metastasis in patients with DTC may be incidentlly detected with [99m]TcO[4] scan. Multinodular goiter with palpable lymph node should always be investigated for exclusion of malignancy. The patients underwent near total thyroidectomy and radical neck dissection; histopathology confirmed the scan findings: