A five-week ulcer under a denture that is not a denture sore
Mr Wong, 67, has worn upper and lower partial dentures for 12 years. He attends asking for new dentures because the lower one 'rubs'. On examination there is a 2 cm by 1.5 cm ulcer on the left posterior mandibular ridge extending into the retromolar region. It has been present for five weeks and has not healed despite him leaving the denture out for the past ten days. The margins are raised and everted, the base is firm and indurated, and it is only mildly tender. He has smoked 20 cigarettes a day for 40 years and drinks about 20 units of alcohol a week. There is a firm, 1.5 cm, non-tender submandibular lymph node on the left that does not move freely. He has lost about 4 kg in three months and mentions his voice has been 'a bit hoarse'. He is not in pain and is not worried; he simply wants impressions taken today.
1. What features of this presentation concern you, and what is your differential diagnosis?
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Red flags present
- Duration over three weeks and failure to heal after removing the denture, which removes the usual traumatic cause.
- Induration and raised, everted margins: a simple denture ulcer is shaped like the denture flange, is soft and heals in 7 to 14 days once the trauma is removed.
- A firm, fixed, non-tender submandibular node. A reactive node is usually tender and mobile; a hard fixed node in this context suggests metastatic spread.
- Site and risk factors: posterior mandible and retromolar region, 40 pack-years of smoking, 20 units of alcohol weekly, age 67.
- Systemic features: 4 kg weight loss and hoarseness, which could indicate spread beyond the oral cavity.
Differential diagnosis
- Squamous cell carcinoma - the leading diagnosis on these features.
- Chronic traumatic ulcer - unlikely with induration and a fixed node.
- Major aphthous ulceration, tuberculosis, syphilis.
- Lymphoma or a salivary gland malignancy.
- Metastatic deposit from an unknown primary.
What I would still check - the whole oral mucosa for a second primary, the floor of mouth and ventral tongue, the tonsils and oropharynx, both necks, cranial nerve examination, and whether the lesion bleeds on palpation. I would record its size and take a photograph.
2. What is your immediate management, and what must you avoid doing?
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Refer urgently. I would make an urgent referral to oral and maxillofacial surgery for assessment and biopsy, targeting review within two weeks. The referral letter would state the key facts explicitly - 'suspected oral malignancy: 5-week indurated ulcer of left posterior mandible, 2 by 1.5 cm, fixed 1.5 cm left submandibular node, 40 pack-year smoker' - so that it is triaged as urgent rather than routine. In Hong Kong this means the appropriate public oral and maxillofacial unit or an urgent hospital pathway.
What to avoid
- Do not adjust the denture and review in two weeks. That is the classic cause of delayed diagnosis in exactly this presentation.
- Do not prescribe empirical antibiotics for a chronic ulcer. It has no effect on a neoplasm and wastes time.
- Do not take impressions for new dentures today.
- Do not tell him it is 'just your dentures rubbing'.
- Do not incise into the lesion to 'see what comes out'.
Other actions - advise him to leave the lower denture out on that side, give analgesia if needed, record the node and lesion in the notes with a diagram, and consider whether an incisional biopsy in primary care is appropriate. The safest answer where a specialist appointment is achievable within days is referral rather than biopsy, because the biopsy must be representative and the site must not compromise later resection.
Follow-up responsibility - log the referral, confirm it was received, and track the result. If he does not attend, the practice must contact him.
3. How would you explain your concern to Mr Wong and obtain his cooperation, given that he is not worried and only wants dentures?
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Principle - be honest without frightening him, and do not collude with his assumption that this is a denture problem.
What I would actually say - 'I am not going to take impressions today. The sore has been there for five weeks and it is not healing the way a denture sore normally would; the edge feels firm, and there is a gland in your neck that I want checked. In someone who has smoked for as long as you have, we have to rule out something more serious than rubbing. The right thing is for you to be seen urgently by a specialist who will look at it and take a small sample.'
What I would avoid - saying 'it is cancer' before histology, and saying 'it is nothing to worry about'.
Supporting the conversation - explain what a biopsy involves, the referral timeline, that he will be contacted with an appointment, and give written information and a contact number. Offer to have a relative present. Ask him to repeat the plan back to check understanding.
Health promotion and prevention - advise stopping smoking and reducing alcohol, and offer referral to a cessation service. Explain that even if this turns out to be benign, the rest of his mouth needs checking.
Documentation - record what was said, that he understood, that he was advised about smoking and alcohol, and the referral details. Closed-loop communication protects the patient and the clinician.