Short notes on Important Diseases of Mouth, Salivary glands & Oesophagus


Oral Cavity

Congenital development disorders

Fordyce’s spots: Numerous yellowish white bodies found on the upper lip as a result of ectopic sebaceous glands.

Lymphoepithelial cyst: Can occur anywhere (i.e.: oral, cervical etc). It’s a cyst whose internal lining is keratinised squamous epithelium, and its outside is lined by a capsule. Within this cyst are multi-lymphoid follicles which contain lymphocytes.

Peutz-Jeghers syndrome: Intestines have hamartomatous polyps, and this is associated with brown black lesions around lips.

Macroglossia: big tongue. You get this if you have three copies of chromosome 21, instead of the normal two.

Microglossia: small tongue. 

Cleft upper lip (hare lip) + or - cleft palate: Cleft palate affects roof of the mouth.

Ankyloglossia: The fraenulum underneath your tongue attaches the tongue to the base of the oral cavity, thus limiting its movement. If you have a very short fraenulum or it consolidates, it limits tongue movement - tongue tie.

Branchial cleft cysts: There are lumps on one side of the neck, which contains fluid. Abnormal development of neck structures.

Xeroderma Pigmentosa: Inherently, the body can repair DNA damaged from UV rays. In this condition, which is inherited, the body is not able to do this. The DNA of skin cells are damaged permanently. It is autosomal recessive (i.e.: need two recessive genes for trait to be seen).

Oral inflammations

Lichen planus: inflammatory condition of the skin. No cause indentified, but allergic reactions that look similar have been identified after use of drugs. It is not infectious or cancerous.

Aphthous ulceration: Round/Oval ulcers on mucous membranes that are not firmly bound to bone. Common areas are: inside of lips, insider of oral cavity, genital areas etc.

Oral candidiasis (aka: thrush, moniliasis, candidiasis): Predominantly caused by candida albicans. Its is a commensal in 30-40% of humans, and commonly affects the oral cavity. Clinically, you see creamy blotches insider oral cavity or tongue. It is an opportunistic infection, which can occur if certain predisposing factors exist: 1) antibiotic treatment, 2) diabetes mellitus, 3) immunocompromised, 4) debilitation.


Other oral conditions
Crohn’s disease: This is an inflammatory bowel condition. Ulcerative colitis is the other variety. Crohn’s can affect any part of the GIT system. See other lectures for more information.

Dilantin therapy: Fibrous hyperplasia of the gingiva can occur with this therapy.

Amyloidosis of tongue: Amyloidosis is basically deposition of proteinatious material called amyloid in the extracellular tissue of organs. In this case, these deposits occur in the tongue.

Leukoplakia & Erythroplasia (erythroplakia)

Leukoplakia: This affects the oral cavity. Patient notice a white patch that is at least 5cm in diameter, and it cannot be rubbed off and not be diagnosed as anything else. It is potentially (i.e.: different types of leukoplakia have different rates of progressiont to cancer) a pre-cancerous lesion.

Erythroplasia: This is basically a red patch/plaque that cannot be categorised as any other disease process. This is also a premalignant lesion.

Premalignant lesions

Tumours of Oral Cavity

Benign lesions
The most common type of benign lesion of oral cavity is: squamous papilloma. It contains core of connective tissue, surrounded by glandular proliferation of mucosa.

Squamous cell carcinoma
This is the commonest tumour of oral cavity. Commonly occurs in older people. Basically, there is abnormal proliferation of mucosal cells. Can involve specifically the: lip, dorsum of tongue, palate. Predisposing factors: tobacco, alcohol, betel nutes (Asians), UV light. Infections such as: candidiasis, human papilloma virus, herpes simplex virus can also lead to squamous cell carcinoma. Premalignant lesions (described in lecture notes) n the vicinity of oral cavity can also lead to this. Histological patterns: moderately differentiated mucosal cells proliferate into submucosa layers, sometimes can be into lumen (exophytic). Then spreads to muscle and regional lymph nodes.
Other malignant neoplasms
Adenocarcinoma / adenosquamous carcinoma of oral cavity, connective tissue neoplasms, malignant melanoma.

Salivary glands

Disorders of secretion

Xerostomia (i.e.: dry mouth): This is a symptom of several diseases. Causes can be: medications (i.e.: antihypertensive, antidepressant, analgesics, diuretics, transhistamines), stress/fear/anxiety, Sjiogren’s syndrome (dry eyes + mouth) – causes fibrotic glands, irradiation sialadenitis (loss of secretory cells).

Sialorrheoa (ptyalism): increased salivary flow. Cause: neurological, acute inflammation of oral cavity.

Salivary calculi: Stones in the salivary glands (i.e.: submandibular & parotids, not sublingual) or salivary ducts (i.e.: submandibular & parotids). M:F = 2:1. Most common beyond 2nd decade of life.

Salivary cysts: Three types à 1) mucous extravasation (too much production), 2) mucous retention (blockage in ducts), 3) ranula (similar to 1&2)

Inflammatory disorders

Acute sialadenitis (inflammation of salivary gland): inflammation most often affects parotid gland (CT scan shows enlarged parotids). Usually caused by bacterial infections due to dehydration of oral cavity (xerostomia). Causative organisms: Strep viridans, Staoh aureus.

Chronic sialadenitis (as above): This occurs chronically due to unresolved acute sialadenitis, or due to strictures or stones. Eventually, inflammation leads to fibrosis of salivary gland.

Chronic recurrent parotitis: Clinically, you get tender parotid glands during GI examination. Usually seen in children and female adults. The parotid ducts are proliferating & dilated, and you get acinar atrophy and fibrosis.

Specific bacterial and granulomatous lesions: GATSS.

Viral infections: CM

Sjogren’s syndrome

This is characterised by dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia). It occurs because the lacrimal and salivary glands are attacked by lymphocytic and other immune cells. 90% are F > 50yrs. Commonly associated with Rheumatoid arthritis, SLE & scleroderma.

Tumours of salivary gland
There is a whole heap. Refer to lecture notes. Just remember the basic sequence: adenoma, carcinoma, non epithelial tumours, malignant lymphomas, 2nd tumours, unclassified tumours, tumour like conditions. I doubt we need to know all this. If so, it’s ridiculous!

Oesophagus

Congenital and development disorders

Heterotopias: This is any deviation of any organ from its natural position.

Congenital cysts + duplications: Cysts might develop within wall of the oesophagus. Essentially, they can impinge on the lumen of the oesophagus, causing problems in the passage of food.

Oesophageal atresia: congenital closure of the oesophagus.
Oesophageal fistula: connections between oesaphus - trachea/bronchi. Food enters the lung, and air enters the oesophagus. Major problems.

Oesophageal webs/rings: congenital narrowing - Dysphagia.

Functional disorders

Achalasia: Basically, the lower oesophageal sphincter fails to open during the food passage process. This is because of neurogenic failure (i.e.: defective relaxation, or increased resting tone of sphincter muscle). Therefore you have mega-oesophagus (2nd year notes).

Mallory Weiss Syndrome: This is a longitudinal tear in the oesophagus at the esophagogastric junction. Associated with: chronic cough, straining at stool, severe hiccups, vomiting and gastric reflux (alcoholism).

Diverticula: Outpouching of the ailementary tract. Can occur in the oesophagus. HIstologically, outpouching contains all visceral layers (mucosa, submucosa, muscularis mucosa, serosa). Three areas: Zenker, Traction, Epiphrenic.

Inflammations – oesophagitis

Reflux oesophagitis: Risk factors: smoking, hiatus hernia, obesity, drugs, duodenal ulcer. Patterns: 1) Reflux, 2) Erosive / ulcerative, 3) Peptic stricture, 4) Barret’s. 1): gastric contents reflux into the lower oesophagus, 2) erosion of the mucosa due to some other factor other than gastric contents, 3) if there is narrowing of the stomach, then stomach contents will back up and flow into the oesophagus, with help from defective LES. Histopathology: 1) usually basal zone contains squamous epithelial cells that are yet to move into the top zones. In oesophagitis, you see more 20% of the epithelium devoted to this region due to high turnover of cells from destruction. 2) elongation of lamina propria papillae, 3) inflammatory cells present in epithelium: eosinophils, neutrophils, lymphocytes.

Barrett’s oesophagus: This occurs when there is prolonged gastric reflux injury to the oesophagus. The squamous cells are replaced by metaplastic columnar cells (more resistant to acid injury). It resembles gastric mucosa rather than oesophageal mucosa. Histopathology: Three types of mucosa have been described. 1) gastric fundic type mucosa with chief and parietal cells. 2) mucosa resembling the cardia region (more mucous cells), 3) intestinal mucosa with villi and goblet cells. Should search for any dysplasia in the histological section - prevent malignancy. Look for nuclei in the basal aspect of epithelial cell (low grade dysplasia), or apical aspect (high grade dysplasia).

Other causes of oesophagitis: 1) ingestion of mucosal irritants (i.e.: alcohol, corrosive agents, alkaline agents, smoking, excessive hot foods), 2) anticancer therapy that is toxic to tumour cells (i.e.: may also affect normal cells), 3) infection: bacteraemia/viraemia (HSV, CMV), 4) fungal infections: candidiasis, 5) uraemia (setting of renal failure).

Other conditions

Oesophageal varices: This is caused due to increased pressure in the oesophageal veins causing dilated, tortous veins - varices. Associated with alcoholic cirrhosis. The reason for dilated tortous veins is because of portal hypertension. Increase pressure causes the systemic circulation to take up the venous blood (i.e.: oesophageal veins are key area of portal-caval anastomoses).

Hiatus hernia: This is caused by the widening of the space between the muscular crus of the diaphragm and the oesophageal wall. This causes the stomach to herniate through the oesophageal hiatus.

Tumours of the oesophagus -

Benign tumours

These tumours of the oesophagus are mesenchymal in origin and lie within the oesophageal wall. Most common are tumours of the smooth muscle of the oesophageal wall - leiomyomas. Polyps can also occur. If polyps contains lipid material - lipoma. If they contain vascular material - vascular polyps. Squamous papilloma can also occur. Benign tumours of the nerves - neurofibroma and all can also occur.

Malignant tumours

Most commonly squamous cell carcinoma & adenocarcinoma of the oesophagus. Secondary tumours can also occur. Other tumours are rare and can occur, such as: malignant melanoma, carcino-sarcoma, adenoid cystic carcinoma.

Squamous cell carcinoma

Risk factors: Male>Female, Alcohol, Tobacco, prolonged oesophagitis, Barett’s oesophagitis, Dietary factors: food carcinogens combined with nutritional deficiencies. Genetic component is not really that great.

Location: 50% - middle 1/3, 30% – lower 1/3, 20% - upper 1/3.

Patterns of growth: Three types seen, 1) protruded (60%) – lesion is exophytic and protrudes into the lumen, 2) diffuse infiltration of the oesophageal wall and no where else. This causes thickening, rigidity and narrowing of lumen. 3) excavated lesions where the cancer becomes necrotic and ulcerates through the oesophageal wall, and may even penetrate into the respiratory tree or aorta.

Adenocarcinomas

Common in lower 1/3 of the oesophageal and associated with Barrett’s mucosa. Histopathology: Microscopically, most tumours are mucin producing and glandular. 


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