Who should an 11mm thyroid nodule patient be referred to?

Referral for 11mm Right Thyroid Nodule

An 11mm thyroid nodule should be referred to an endocrinologist for ultrasound risk stratification and consideration of ultrasound-guided fine-needle aspiration biopsy (FNA), as this size exceeds the 10mm threshold where FNA is recommended for most nodules. 1, 2

Initial Specialist Selection

• Refer to an endocrinologist first for comprehensive evaluation, ultrasound characterization using TIRADS classification, and FNA if indicated based on sonographic features 1, 3
• Endocrinologists are best positioned to perform initial risk stratification and coordinate the diagnostic workup for thyroid nodules 3, 4

When to Refer Directly to Endocrine Surgery

Bypass endocrinology and refer directly to an endocrine surgeon in the following specific circumstances:

• If FNA has already been performed and shows malignant (Bethesda VI) or suspicious (Bethesda V) cytology requiring total or near-total thyroidectomy 1, 2
• If there is confirmed metastatic, multifocal, or familial differentiated thyroid carcinoma, regardless of nodule size 2
• If follicular neoplasia (Bethesda IV) is found with normal TSH and "cold" appearance on thyroid scan, as surgical excision is required for definitive diagnosis 1, 2

Critical High-Risk Features That Modify Urgency

The following clinical features warrant more urgent referral and lower the threshold for FNA even in smaller nodules:

• History of head and neck irradiation (increases malignancy risk approximately 7-fold) 2
• Family history of thyroid cancer, particularly medullary carcinoma or familial syndromes 2
• Age <15 years or male gender (higher baseline malignancy probability) 2
• Rapidly growing nodule suggesting aggressive biology 2
• Firm, fixed nodule on palpation indicating potential extrathyroidal extension 2
• Vocal cord paralysis or compressive symptoms (dysphagia, dysphonia, dyspnea) suggesting invasive disease 2, 5
• Suspicious cervical lymphadenopathy on examination 2

Suspicious Ultrasound Features Requiring FNA

If ultrasound has already been performed, the following features indicate high priority for endocrinology referral and FNA:

• Microcalcifications (highly specific for papillary thyroid carcinoma) 2
• Marked hypoechogenicity (solid nodules darker than surrounding thyroid) 2
• Irregular or microlobulated margins (infiltrative borders rather than smooth contours) 2
• Absence of peripheral halo (loss of thin hypoechoic rim) 2
• Central hypervascularity (chaotic internal vascular pattern) 2
• Solid composition (higher malignancy risk than cystic) 2

Expected Diagnostic Pathway After Referral

The endocrinologist will typically follow this algorithm:

1. Measure serum TSH to determine thyroid function status 1, 3
2. Perform high-resolution thyroid ultrasound with TIRADS classification 1, 2
3. Proceed with ultrasound-guided FNA for nodules ≥10mm (which includes this 11mm nodule), particularly if suspicious features are present 1, 2, 3
4. Consider measuring serum calcitonin to screen for medullary thyroid cancer, which has higher sensitivity than FNA alone 2
5. Perform complete neck ultrasound to evaluate cervical lymph nodes for suspicious features 2

Management Based on FNA Results

• Bethesda II (Benign): Surveillance with repeat ultrasound at 12-24 months, as malignancy risk is only 1-3% 1, 2
• Bethesda III (AUS/FLUS) or IV (Follicular Neoplasm): Consider molecular testing (BRAF, RAS, RET/PTC, PAX8/PPARγ) or repeat FNA 1, 2
• Bethesda V (Suspicious) or VI (Malignant): Immediate referral to endocrine surgeon for total or near-total thyroidectomy 1, 2

Common Pitfalls to Avoid

• Do not delay referral for nodules ≥10mm, as this is the established size threshold for FNA consideration 1, 3
• Do not rely on thyroid function tests alone to assess malignancy risk, as most thyroid cancers present with normal thyroid function 2
• Do not skip ultrasound characterization before FNA, as TIRADS classification guides appropriate management 1, 2
• Do not perform radionuclide scanning in euthyroid patients to determine malignancy risk, as ultrasound features are far more predictive 2
• Do not override a reassuring FNA when worrisome clinical findings persist, as false-negative results occur in up to 11-33% of cases 2

Special Consideration for Symptomatic Nodules

• If the patient has pain, discomfort, or compressive symptoms, this warrants specialist evaluation regardless of size, as these symptoms may indicate need for intervention 5
• Symptomatic nodules may require surgical intervention or thermal ablation techniques even if cytologically benign 1, 5