What is the best course of action for an adult patient with a history of hyperthyroidism (overactive thyroid) presenting with a neck mass, hoarseness, and difficulty swallowing, despite a normal thyroid ultrasound?

Urgent Evaluation for Malignancy with Contrast-Enhanced CT Neck and Laryngoscopy

This patient requires immediate evaluation for head and neck malignancy with contrast-enhanced CT neck (or MRI neck with contrast) and direct visualization of the larynx, base of tongue, and pharynx, despite the normal thyroid ultrasound. The combination of hoarseness, dysphagia, and a neck mass in an adult represents high-risk features for malignancy that demand urgent workup, regardless of thyroid imaging results 1.

Why This Is Not a Thyroid Problem

• The normal thyroid ultrasound effectively excludes thyroid pathology as the source of the neck mass 1
• The mass is likely located outside the thyroid gland itself, representing either lymphadenopathy from an occult primary malignancy or a non-thyroidal neck mass 1
• The history of hyperthyroidism is a red herring in this clinical scenario—hyperthyroidism does not cause neck masses with compressive symptoms like hoarseness and dysphagia 2, 3, 4

Critical Red Flags Present in This Patient

Hoarseness and dysphagia are alarm symptoms that suggest either:

• Direct invasion of the recurrent laryngeal nerve or larynx by tumor 1
• Mass effect from a large malignant lymph node compressing the aerodigestive tract 1

The American Academy of Otolaryngology-Head and Neck Surgery emphasizes that nontender neck masses are more suspicious for malignancy than tender masses 1. The absence of pain or infection history further elevates concern for neoplastic disease 1.

Immediate Diagnostic Algorithm

Step 1: Cross-Sectional Imaging (Within Days)

• Order contrast-enhanced CT neck immediately as the preferred initial imaging modality for a nonpulsatile neck mass at risk for malignancy 1
• CT provides superior spatial resolution and can identify the precise location of the mass, assess for nodal necrosis (highly specific for malignancy), and guide the search for an occult primary tumor in the upper aerodigestive tract 1
• MRI neck with contrast is equally appropriate if CT is contraindicated 1

Step 2: Direct Laryngoscopy (Concurrent or Immediately After Imaging)

• The patient must undergo visualization of the larynx, base of tongue, and pharynx to identify a potential primary malignancy 1
• This requires either flexible laryngoscopy in the office or examination under anesthesia if office examination is inadequate 1
• The American Academy of Otolaryngology-Head and Neck Surgery provides a strong recommendation that this targeted physical examination is mandatory for patients with neck masses at increased risk for malignancy 1

Step 3: Tissue Diagnosis

• Fine-needle aspiration (FNA) should be performed as the initial pathologic test once imaging is complete 5
• FNA is rapid, cost-effective, and has high sensitivity and specificity for diagnosing malignancy 5
• Open biopsy should only be performed after examination of the upper aerodigestive tract under anesthesia and when diagnosis remains uncertain after FNA and imaging 5

Common Pitfalls to Avoid

Do not assume the neck mass is related to the hyperthyroidism history 2, 3. Hyperthyroidism from Graves' disease or toxic nodular goiter does not cause isolated neck masses with compressive symptoms—these conditions cause diffuse thyroid enlargement or nodules within the thyroid gland itself, which would have been detected on ultrasound 2, 3, 6, 4.

Do not delay evaluation with empiric antibiotics unless there is clear evidence of bacterial infection (fever, erythema, fluctuance) 5. The absence of pain and infection history makes infectious etiology unlikely 1.

Do not proceed directly to open biopsy without first obtaining cross-sectional imaging and attempting FNA 5. Open biopsy before adequate workup can compromise subsequent surgical management if malignancy is present 5.

Malignancy Risk Stratification

In adults with neck masses, the differential overwhelmingly favors malignancy when:

• The mass persists beyond 2-3 weeks 1
• Associated symptoms include hoarseness or dysphagia 1
• The mass is nontender 1
• For patients >40 years of age, especially with smoking history, malignancy is the most likely diagnosis 1

The most common scenario is metastatic squamous cell carcinoma from an occult primary in the oropharynx, larynx, or hypopharynx 1. With the rise of HPV-related oropharyngeal carcinomas, vigilance for malignancy is warranted across all adult age groups 1.

Timeline for Evaluation

This evaluation should be completed within 1-2 weeks maximum 1. The American Academy of Otolaryngology-Head and Neck Surgery emphasizes the importance of timely diagnosis for neck masses at increased risk for malignancy 1. Delays in diagnosis can adversely affect treatment outcomes and prognosis 1.