What is the initial management for a patient with a fine-needle aspiration (FNA) result showing nodular cystic goiter?

Management of Nodular Cystic Goiter on FNA

For a patient with FNA showing nodular cystic goiter (benign cytology), clinical observation with periodic surveillance is the appropriate initial management, reserving intervention only for compressive symptoms, cosmetic concerns, or development of suspicious features. 1, 2

Understanding the FNA Result

The FNA diagnosis of "nodular cystic goiter" falls into Bethesda Category II (benign), which includes nodular goiter, colloid goiter, and hyperplastic/adenomatoid nodules, carrying a malignancy risk of only 1-3%. 1 This benign cytology result is highly reliable for ruling out malignancy, with diagnostic accuracy approaching 95%. 3

However, a reassuring FNA should not override worrisome clinical findings, as false-negative results occur in up to 11-33% of cases. 1, 4 If clinical suspicion remains high despite benign cytology, additional evaluation is warranted.

Initial Management Algorithm

For Asymptomatic Patients with Benign FNA:

• Measure serum TSH to assess thyroid function and determine if autonomous function is present. 5, 6
• Perform or review thyroid ultrasound to document baseline nodule characteristics, assess for suspicious features (microcalcifications, irregular margins, marked hypoechogenicity, central hypervascularity), and evaluate cervical lymph nodes. 3, 5
• Institute surveillance protocol: Yearly clinical evaluation with TSH measurement and thyroid palpation is sufficient for small, stable, asymptomatic multinodular goiters with benign FNA results. 2, 6

Surveillance Schedule:

• Repeat ultrasound at 12-24 months to assess for interval growth or development of suspicious features. 3
• After initial 12-month follow-up, continue annual ultrasound for benign nodules. 5
• Repeat FNA if the nodule increases by ≥3 mm in any dimension or develops new suspicious ultrasound features (microcalcifications, irregular borders, marked hypoechogenicity). 3, 5

Indications for Intervention

Surgery is indicated when:

• Compressive symptoms are present and clearly attributable to the goiter (dysphagia, dyspnea, choking sensation, airway obstruction). 2, 6, 7
• Cosmetic concerns are significant and patient-driven. 3, 2
• Large goiters (>4 cm) causing symptoms, due to increased false-negative rate of FNA and higher risk of compressive symptoms. 3, 8
• Development of suspicious features on follow-up ultrasound despite initially benign cytology. 3
• Repeat FNA shows malignant or suspicious cytology (Bethesda V/VI). 3, 6

Radioactive iodine may be considered when:

• Autonomous function is documented (suppressed TSH with elevated T4) and uptake is adequate on radioiodine scan. 9, 7
• Surgery is contraindicated or patient prefers non-surgical management for toxic multinodular goiter. 2, 7

What NOT to Do

• Do not routinely use levothyroxine suppression therapy for nontoxic multinodular goiter, as it is often unsuccessful and carries risk of iatrogenic hyperthyroidism, particularly in patients with suppressed TSH. 2, 9
• Do not assume all nodules are benign simply because one nodule had benign FNA—malignancy is just as common in multinodular goiter as in solitary nodules. 9, 6
• Do not perform FNA on every nodule in a multinodular goiter—select the largest nodule, most suspicious nodule by ultrasound features, or any nodule with high-risk clinical features. 3, 8
• Do not override benign FNA results without cause, but maintain appropriate clinical vigilance for worrisome features (rapid growth, firm/fixed nodule, vocal cord paralysis, suspicious lymphadenopathy). 1, 4

High-Risk Features Requiring Closer Surveillance or Repeat FNA

Even with benign initial cytology, closer follow-up or repeat FNA is warranted if any of these features are present:

• History of head and neck irradiation (increases malignancy risk approximately 7-fold). 3, 4, 5
• Family history of thyroid cancer or genetic syndromes (MEN 2A/2B, familial adenomatous polyposis, Carney complex, Cowden's syndrome). 4, 5, 8
• Age <15 years or male gender (higher baseline malignancy probability). 4, 5
• Rapidly growing nodule, firm/fixed nodule on palpation, or vocal cord paralysis. 4, 5
• Suspicious cervical lymphadenopathy. 3, 4, 5

Role of Molecular Testing

Molecular testing is generally NOT indicated for Bethesda II (benign) nodules, as the pretest probability of malignancy is so low (1-3%) that molecular markers add minimal clinical value. 3 Molecular testing should be reserved for Bethesda III (AUS/FLUS) or IV (follicular neoplasm) categories where management decisions are uncertain. 3

Common Pitfalls to Avoid

• Performing unnecessary surgery on asymptomatic benign nodules leads to overtreatment without improving mortality or quality of life. 3
• Failing to obtain adequate ultrasound characterization of all nodules in a multinodular goiter may miss a dominant suspicious nodule requiring FNA. 6, 8
• Using levothyroxine suppression indiscriminately in patients with normal or suppressed TSH can cause iatrogenic thyrotoxicosis without proven benefit. 2, 9
• Assuming cystic nodules are always benign—continue evaluation until diagnosis is certain, as cystic masses can harbor malignancy. 1