Tumours of the oral cavity
How tobacco, areca nut and alcohol drive the oral lining through white and red patches and dysplasia to squamous cell carcinoma, how it invades and reaches the neck nodes, and the odontogenic tumours of the jaws such as ameloblastoma.
By the end, you can
- Describe the lining, boundaries and lymphatic drainage of the oral cavity, and relate them to where oral cancers arise and spread.
- Distinguish leukoplakia, erythroplakia and oral submucous fibrosis as potentially malignant disorders, and explain why their risks differ.
- Explain how tobacco, areca nut and alcohol cause oral epithelial dysplasia and squamous cell carcinoma, including field cancerisation.
- Describe the gross and microscopic appearance of oral squamous cell carcinoma and of ameloblastoma.
- Explain why depth of invasion and neck nodes are central to the stage of an oral cancer.
What it is
Oral cavity tumours arise in the lips, cheek lining, gums, floor of the mouth, hard palate, front two-thirds of the tongue and the jaws. Over nine in ten malignant ones are squamous cell carcinomas of the lining, often preceded by oral potentially malignant disorders such as leukoplakia; the jaws also host odontogenic tumours, of which ameloblastoma is the most important.
3 types to tell apart
- Oral potentially malignant disorders
- Leukoplakia, erythroplakia, proliferative verrucous leukoplakia and oral submucous fibrosis: visible changes with a raised but variable risk of cancer.
- Oral squamous cell carcinoma
- From the squamous lining through dysplasia; tobacco, areca nut and alcohol are the main causes; spreads to the neck nodes.
- Odontogenic tumours
- From tooth-forming epithelium or mesenchyme inside the jaws; ameloblastoma is benign but locally aggressive.
US spelling: tumours → tumors.
Normal function
A squamous-lined cavity over muscle and bone
The oral cavity runs from the lips back to the junction of the and and the V-shaped line of large papillae on the tongue. It includes the cheek (buccal) lining, the gums over the tooth-bearing bone, the floor of the mouth, the hard palate and the front two-thirds of the . The , soft palate and tonsils belong to the oropharynx, whose cancers have different causes.
All of it is lined by stratified squamous epithelium on a basement membrane, renewed from its basal cells. Where chewing rubs hardest (gums, hard palate, the ) it is keratinised; on the cheeks, floor of the mouth and underside of the tongue it is thinner and non-keratinised, so dissolved carcinogens cross it more easily. Below lie a vascular lamina propria with minor salivary glands, then muscle or bone.
Lymph drains to the submental and submandibular nodes and on to the deep cervical chain; lymphatics near the midline of the tongue reach both sides of the neck. Teeth form in the jaws from odontogenic epithelium, and small rests of it remain in the bone for life.
Underlying change · Step 1 of 5
White and red patches: potentially malignant disorders
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Carcinogens, field cancerisation and oral epithelial dysplasia
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Oral squamous cell carcinoma: ulcer, induration and invasion
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Odontogenic tumours: ameloblastoma expands the jaw
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
Neck nodes, depth, grade and the effects on the body
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 9 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .