What are the next steps for a 35-year-old female with a suspected papillary thyroid carcinoma (PTC) diagnosis from a Fine Needle Aspiration (FNA) of a left thyroid cyst?

Management of Suspected Papillary Thyroid Carcinoma on FNA

For a 35-year-old female with FNA showing suspicion of papillary thyroid carcinoma, proceed directly to surgical resection with thyroidectomy after completing preoperative staging with neck ultrasound and TSH measurement. 1

Immediate Next Steps

1. Expert Pathology Review

• Have the FNA cytology slides reviewed by a pathologist with specific expertise in thyroid disorders before proceeding to surgery. 1
• This is critical because FNA is highly sensitive for papillary thyroid carcinoma, but false-negative results can occur, and expert review ensures accurate diagnosis 1
• The cytology categorization of "suspicious for papillary carcinoma" falls into the highest-risk FNA category and typically warrants surgical intervention 1

2. Complete Preoperative Staging Workup

Obtain the following studies before surgery: 1

• Neck ultrasound of thyroid and central compartment to assess for bilateral nodularity, extrathyroidal extension, and lymph node involvement 1
• Lateral neck ultrasound to evaluate for suspicious lymphadenopathy 1
• Serum TSH level (higher TSH levels are associated with increased risk of differentiated thyroid cancer) 1
• FNA of any clinically suspicious lymph nodes identified on ultrasound 1

3. Determine Extent of Initial Surgery

The surgical approach depends on specific preoperative findings: 2

Proceed with Total Thyroidectomy if ANY of the following are present:

• Bilateral nodularity on ultrasound (this is an absolute indication regardless of favorable cancer features) 2
• Suspicious cervical lymph nodes on imaging or clinical examination 2
• Tumor >4 cm in diameter 2
• Evidence of extrathyroidal extension on imaging 2
• Aggressive histologic variants suspected (tall cell, columnar cell, poorly differentiated features) 2
• History of head/neck radiation exposure 2

Lobectomy May Be Considered Only If:

• Unifocal disease ≤4 cm 2
• No bilateral nodularity 2
• No extrathyroidal extension 2
• No suspicious lymph nodes 2
• No prior radiation exposure 2

Critical Pitfalls to Avoid

Do not delay surgery for additional molecular testing - the FNA diagnosis of "suspicious for papillary carcinoma" is sufficient to proceed with surgical management 1

Do not perform lobectomy if preoperative ultrasound reveals multiple nodules in the contralateral lobe - bilateral nodularity mandates total thyroidectomy regardless of favorable features of the known cancer 2

Do not rely solely on FNA to rule out malignancy in worrisome clinical scenarios - false-negative FNA results can occur, and clinical judgment should override reassuring cytology when clinical findings are concerning 1

Be aware that FNA-induced changes can rarely cause complete obliteration of thyroid nodules - if the cytology is definitive for papillary carcinoma but the surgical specimen shows only hemorrhage and fibrosis, the cytologic diagnosis should be considered representative 3

Lymph Node Management During Surgery

Therapeutic central neck dissection should be performed if suspicious lymph nodes are identified intraoperatively, but prophylactic central neck dissection is not mandatory in clinically and radiologically node-negative cases with favorable pathology 2

Post-Surgical Management

After surgical resection, final risk stratification depends on complete pathologic findings from the thyroidectomy specimen, including tumor size, multifocality, extrathyroidal extension, and lymph node status 2

Examine the surgical specimen carefully for additional foci of papillary carcinoma - these are found in 44% of completion thyroidectomy cases and significantly impact risk stratification and decisions about radioactive iodine therapy 2