What is the cause and treatment of a lump under the chin?

Evaluation and Management of a Lump Under the Chin

A lump under the chin requires immediate risk stratification for malignancy based on specific clinical features, with high-risk patients needing urgent imaging and specialist referral within days, not weeks. 1, 2

Immediate Risk Assessment

Determine if the patient meets high-risk criteria for malignancy using the following features:

High-Risk Historical Features

• Age >40 years 1, 2
• Mass present ≥2 weeks without significant fluctuation or of uncertain duration 1, 2
• Tobacco and/or alcohol use 1, 2
• Previous head and neck cancer or radiation exposure 2
• Constitutional symptoms (unexplained weight loss, fever >101°F) 1
• Aerodigestive symptoms: difficulty or pain with swallowing, voice changes, throat pain, mouth sores, or ear pain 1, 2

High-Risk Physical Examination Features

• Size >1.5 cm 1, 2
• Firm or hard consistency 1, 3
• Fixed to adjacent tissues 1, 2
• Ulceration of overlying skin 1, 2
• Nontender mass (more suspicious for malignancy than tender mass) 1

Critical Context: Malignancy Risk

Approximately half of all adult neck masses are malignant, with head and neck squamous cell carcinoma being the most common cause. 2 In patients >40 years old with cystic neck masses, up to 80% are malignant. 4, 5 HPV-positive oropharyngeal cancers are rising rapidly and often present as neck masses that may be cystic and mistaken for benign lesions. 1

Management Algorithm

For HIGH-RISK Patients (Meeting ≥1 Criterion Above):

1. Order immediate imaging:

• Contrast-enhanced CT or MRI of the neck 2, 4
• CT provides soft tissue and bone detail with brief scan time 2
• MRI offers superior soft tissue detail without radiation 2

2. Perform or refer for targeted physical examination:

• Visualize the larynx, base of tongue, and pharynx (requires flexible laryngoscopy or mirror laryngoscopy) 1, 2
• Examine oral cavity (remove dentures, inspect all surfaces, palpate floor of mouth) 1
• Examine oropharynx (check for tonsil asymmetry, masses, or ulcers) 1
• Palpate neck and thyroid gland for additional masses 1
• Examine skin and scalp for primary lesions 2

3. Obtain tissue diagnosis:

• Perform fine-needle aspiration (FNA) instead of open biopsy when diagnosis remains uncertain after imaging 1, 2, 4
• FNA is the preferred initial tissue sampling method for high-risk neck masses 2, 4
• Core needle biopsy guided by ultrasound if FNA is non-diagnostic or lymphoma suspected (sensitivity 92%) 4

4. Refer urgently to otolaryngology specialist within days, not weeks 2, 5

5. Educate patient about increased malignancy risk and importance of timely follow-through with all testing 1, 2

For LOW-RISK Patients (No High-Risk Features):

1. Advise patient of criteria that would trigger need for additional evaluation:

• Mass gets larger 1
• Mass does not go away completely 1
• Mass goes away but returns 1
• Development of any high-risk symptoms listed above 1

2. Document follow-up plan:

• Patient should check mass size weekly using fingertips 1
• Mass from infection should resolve completely or return to much smaller size within 2-3 weeks 1
• Ensure documented plan for reassessment if mass persists 1

Critical Pitfalls to Avoid

Do NOT prescribe empiric antibiotics without clear signs of bacterial infection (fever, erythema, fluctuance, recent upper respiratory infection). 1, 2, 4 This delays cancer diagnosis and is particularly dangerous in high-risk patients. 4, 5

Do NOT perform open biopsy before imaging and specialist evaluation. 4, 5 This can seed tumor cells and worsen outcomes. 4, 5 If diagnosis remains uncertain after FNA and imaging, examination of the upper aerodigestive tract under anesthesia should precede open biopsy. 1, 2

Do NOT assume cystic masses are benign. 1, 2 Continue evaluation until diagnosis is obtained, as cystic metastases are common in head and neck cancers, especially HPV-positive oropharyngeal carcinomas. 1, 4

Common Benign Causes to Consider

Normal anatomic structures often mistaken for pathologic masses include submandibular glands, hyoid bone, transverse process of C2, and carotid bulb. 1 However, in the submental/chin region specifically, infectious causes (lymphadenitis from dental or oral infections) are common in low-risk patients. 1 Rare benign tumors can occur but require tissue diagnosis to exclude malignancy. 6, 7

Timeline Expectations

• Biopsy results should be available within 1 week; if not, patient should contact provider 2, 5
• High-risk patients require specialist referral within days 2, 5
• Low-risk patients with presumed infectious etiology should show significant improvement within 2-3 weeks 1