Extrathyroidal uptake from thyroid carcinoma on 99mTc-pertechnetate scintigraphy

Area of Science:

• Nuclear medicine
• Oncology
• Radiology

Background:

• Thyroid cancer diagnosis often involves imaging techniques.
• 99mTc-pertechnetate (99mTcO4) is commonly used for thyroid scintigraphy.
• Unusual uptake patterns require careful interpretation.

Observation:

• Three young female patients presented with unexpected positive lymph node uptake on 99mTcO4 scans.
• Two patients were diagnosed with well-differentiated thyroid carcinoma (DTC) with nodal metastasis.
• The third patient had confirmed thyroid carcinoma with a neck mass post-surgery.

Findings:

• 99mTcO4 scintigraphy can incidentally detect metastatic foci in patients with DTC.
• Extra-thyroidal uptake on routine scans may indicate thyroid carcinoma with regional metastases.
• Histopathology confirmed scan findings in all three cases post-thyroidectomy and neck dissection.

Implications:

• Routine thyroid scans can identify occult metastatic disease in thyroid cancer.
• Palpable lymph nodes in multinodular goiter warrant investigation for malignancy.
• Early detection of nodal metastasis through imaging improves patient management and prognosis.