What is the next step in managing a nonspecific subcutaneous mass in the anterior neck, as identified by sonographic evaluation?

Management of Nonspecific Subcutaneous Anterior Neck Mass

For this small (8mm), superficial, nonspecific subcutaneous mass in the anterior neck, fine-needle aspiration (FNA) should be performed first rather than proceeding directly to excisional biopsy, as FNA is the recommended initial diagnostic test for neck masses at increased risk for malignancy. 1

Risk Stratification

This mass meets criteria for increased malignancy risk based on the following characteristics:

• Size >1.5 cm is NOT met (this mass is only 8mm), which is actually reassuring 1
• Location and duration: The mass warrants evaluation given its presence without clear infectious etiology 1
• Physical characteristics: The hypoechoic appearance on ultrasound is nonspecific and requires tissue diagnosis 1

Recommended Diagnostic Algorithm

Step 1: Obtain Cross-Sectional Imaging

• Order CT neck with contrast (or MRI with contrast if CT is contraindicated) to characterize the mass, evaluate its relationship to surrounding structures, and assess for additional findings 1
• This imaging should be obtained before or concurrently with tissue sampling 2

Step 2: Perform Fine-Needle Aspiration (FNA)

• FNA is strongly recommended as the first-line tissue sampling technique rather than excisional biopsy 1
• FNA offers high sensitivity and specificity, minimal discomfort, low complication rate (including minimal risk of tumor seeding), and is cost-effective 1, 2
• Ultrasound-guided FNA is preferred as it increases specimen adequacy and diagnostic yield 1

Step 3: If FNA is Non-Diagnostic

• Repeat FNA with ultrasound guidance if initial results are inadequate or indeterminate 1, 2
• Consider core needle biopsy if repeat FNA remains non-diagnostic, as core biopsy has 95% adequacy rate and 94-96% accuracy 1, 3
• Core biopsy uses a slightly larger needle and obtains more tissue while maintaining low complication rates 1

Step 4: Excisional Biopsy as Last Resort

• Excisional biopsy should only be performed after FNA (and potentially core biopsy) have failed to yield a diagnosis 1
• This approach is more invasive, requires operating room time and anesthesia, and carries higher risks including bleeding, infection, scarring, and nerve injury 1

Critical Pitfalls to Avoid

• Do NOT proceed directly to excisional biopsy without first attempting FNA, as this exposes the patient to unnecessary surgical risks 1
• Do NOT prescribe antibiotics unless there are clear signs of bacterial infection (warmth, erythema, fever, tenderness), as most adult neck masses are neoplastic rather than infectious 1
• Do NOT assume a small mass is benign based solely on size, as malignancy can present in masses of any size 1
• Ensure adequate follow-up within 1 week of any biopsy to review results and plan next steps 1

Special Considerations

• Given the superficial subcutaneous location and small size (8mm), this mass has a somewhat lower pre-test probability of malignancy compared to deeper, larger masses 1
• However, definitive tissue diagnosis is still required given the nonspecific imaging findings 1
• If the mass proves to be cystic on FNA, continue evaluation until a definitive diagnosis is obtained, as cystic masses can still harbor malignancy 1