What is the management approach for a patient with squamous cell carcinoma (SCC) of the tongue with level 2 node involvement and an incidental Thyroid Imaging, Reporting and Data System (TI-RADS) 4 thyroid nodule on the left lobe of the thyroid?

Management of Tongue Squamous Cell Carcinoma with Level 2 Node and Incidental TI-RADS 4 Thyroid Nodule

The management of this case requires surgical resection of the primary tongue SCC with neck dissection, followed by adjuvant therapy based on pathological findings, while the thyroid nodule should undergo fine needle aspiration biopsy separately.

Primary Tongue SCC Management

Surgical Approach

• Primary surgical resection is the standard of care for oral cavity SCC with nodal involvement 1
• The surgical approach should include:
  • Resection of the primary tumor with adequate margins (at least 5-10mm)
  • Ipsilateral selective neck dissection (levels I-IV) for the level 2 node involvement
  • Consider bilateral neck dissection if the tumor approaches midline

Adjuvant Therapy

• Postoperative radiation therapy (PORT) is indicated due to the presence of nodal metastasis 1
• Recommended dose: 60-66 Gy at 2 Gy/fraction once daily to the tumor bed and involved lymph node regions 1
• Adjuvant chemoradiation therapy (CRT) should be added if any of these high-risk features are found:
  • Extracapsular nodal extension
  • Positive surgical margins
  • Multiple positive nodes
  • Perineural invasion
  • Lymphovascular invasion

Timing Considerations

• Time from surgery to completion of PORT should be kept as short as possible, ideally <85 days 1
• This timing factor may be more important than the specific radiation dose 1

Management of Incidental TI-RADS 4 Thyroid Nodule

Diagnostic Workup

• TI-RADS 4 thyroid nodules require fine needle aspiration biopsy (FNAB) based on ACR guidelines 1
• The workup should be conducted separately from the primary SCC management
• Ultrasound-guided FNAB is the preferred approach for accurate sampling

Timing of Thyroid Evaluation

• The thyroid nodule evaluation should not delay the treatment of the tongue SCC
• FNAB can be performed:
  1. Before SCC surgery if it doesn't delay primary treatment
  2. During the SCC surgery if convenient
  3. After completion of SCC treatment if necessary

Management Based on FNAB Results

• Benign cytology: Follow-up with ultrasound in 1-2 years
• Malignant cytology: Plan for thyroidectomy after completion of SCC treatment
• Indeterminate cytology: Consider molecular testing and/or follow-up based on risk stratification

Surveillance and Follow-up

For Tongue SCC

• Clinical examination every 1-3 months for the first year
• Imaging (CT/MRI with contrast) at 3 months post-treatment and then as clinically indicated
• PET-CT if recurrence is suspected but not visualized on conventional imaging

For Thyroid Nodule

• If FNAB is benign: Follow-up ultrasound in 12-24 months
• If FNAB is malignant or suspicious: Management according to thyroid cancer guidelines
• Monitor thyroid function if neck radiation is administered

Special Considerations

Potential for Collision Tumors

• While rare, collision metastases of oral SCC and papillary thyroid carcinoma to the same lymph node have been reported 2, 3
• This possibility should be considered during pathological examination of the neck dissection specimen

Impact on Staging and Treatment Planning

• The presence of a thyroid nodule does not change the staging or initial management of the tongue SCC
• However, if thyroid malignancy is confirmed, this would represent a second primary cancer requiring separate management

Radiation Planning Considerations

• If radiation therapy is needed for the tongue SCC, the radiation field will likely include parts of the thyroid gland
• This may affect future management of the thyroid nodule and thyroid function

Pitfalls to Avoid

• Do not delay treatment of the tongue SCC to evaluate the thyroid nodule
• Do not assume the level 2 node is related to the thyroid nodule rather than the tongue SCC
• Do not neglect follow-up of the thyroid nodule after completion of SCC treatment
• Do not automatically include the thyroid nodule in the radiation field unless there is evidence of thyroid malignancy with neck involvement