What could be causing painful oral ulcers under my tongue and a swollen lymph node that have persisted for more than 3 weeks?

Urgent Specialist Referral Required for Possible Oral Malignancy

Any oral ulcer persisting beyond 2-3 weeks, especially when accompanied by a swollen lymph node, requires immediate specialist referral to rule out squamous cell carcinoma or other serious pathology. 1, 2

Why This Requires Urgent Evaluation

The combination of persistent oral ulcers (>3 weeks) and lymphadenopathy is a red flag presentation that mandates specialist assessment. 1 The ESMO guidelines explicitly state that "chronic sore tongue or non-healing ulcers" along with "neck masses" are symptoms that should prompt immediate evaluation for squamous cell carcinoma of the head and neck. 1

Pathological confirmation through biopsy is mandatory for any persistent oral ulcer. 1

Immediate Action Steps

1. Specialist Referral (Within Days, Not Weeks)

• Refer to an oral medicine specialist or head and neck surgeon immediately for evaluation of possible oral cavity squamous cell carcinoma. 1, 2
• Oral medicine specialists can perform specialized diagnostic procedures including biopsies and coordinate multidisciplinary care when needed. 2
• Do not delay referral for "trial of treatment" when an ulcer has already persisted 3+ weeks. 2

2. Clinical Examination Details to Document

• Exact location and size of ulcer(s) under the tongue. 1
• Characteristics of the ulcer: indurated borders, rolled edges, fixation to underlying tissue (all concerning for malignancy). 1
• Lymph node characteristics: size (>1.5 cm is particularly concerning), location, consistency (hard/firm suggests malignancy), mobility, and whether unilateral or bilateral. 1
• Risk factor assessment: tobacco use, alcohol consumption, HPV exposure history, poor oral hygiene, ill-fitting dentures, betel nut chewing. 1

3. What the Specialist Will Do

• Contrast-enhanced CT or MRI to assess the primary lesion and regional lymph nodes. 1
• Biopsy for histopathological examination is mandatory to establish diagnosis. 1, 2
• Complete blood count, liver enzymes, serum creatinine, albumin for baseline assessment. 1
• Chest imaging to evaluate for distant metastases or second primary lung cancer in high-risk patients. 1

Critical Differential Diagnoses to Consider

While malignancy is the primary concern with this duration and presentation, the specialist will also evaluate for:

Autoimmune/Inflammatory Causes

• Pemphigus vulgaris, mucous membrane pemphigoid, erosive lichen planus can present with chronic oral ulcers and may have associated lymphadenopathy. 3, 4
• These require special diagnostic tests including direct immunofluorescence and serum antibody tests. 2

Infectious Causes

• Chronic infections such as tuberculosis or deep fungal infections can cause persistent oral ulcers with lymphadenopathy. 2
• Tongue abscess can present with severe pain and swelling but typically has acute onset (days, not weeks) and fluctuance on palpation. 5, 6

Hematologic Malignancies

• Lymphoma can present as persistent oral ulcers with lymphadenopathy. 2

Common Pitfalls to Avoid

• Do not treat empirically with topical corticosteroids without establishing a diagnosis when an ulcer has persisted >3 weeks. 2
• Do not assume this is a benign aphthous ulcer – recurrent aphthous ulcers typically heal within 7-14 days. 2, 7
• Do not perform inadequate or superficial biopsies that may miss diagnostic features. 2
• Do not overlook the significance of the lymphadenopathy – this substantially increases concern for malignancy or systemic disease. 1

What NOT to Do While Awaiting Specialist Evaluation

• Avoid hot, spicy, sharp, or hard foods that may cause additional trauma. 1
• Maintain good oral hygiene with gentle brushing and warm saline rinses. 1, 2
• You may use benzydamine hydrochloride oral rinse for symptomatic pain relief while awaiting evaluation. 7
• Do not delay referral – the 3-week threshold has already been exceeded. 2