Gastrointestinal system Part II

The oesophagus

A muscular tube

Conduction of food and drink

Sphincters at top and bottom

Histology

Non-keratinising squamous epithelium

Submucosa Lamina properia Muscularis mucosa Muscular layer Advanticia No mesothelia coverage

Congenital and mechanical disorders (1)

Atresia – often with fistula to trachea Hiatus hernia (presence of stomach in

thoracic cavity) – due to increased intra-abdominal pressure

Sliding hernia>95% Paraesophageal<5%

Hiatal hernia……..

Heart burn&Regurgitation Reflux esophagitis Esophageal ulcer Strangulation

…Mechanical disorders (2)

Achalasia Failure of relaxation of lower

oesophageal sphincter (destruction or degeneration of nerve plexus)

Similar features in Chagas’ disease (South American trypanosomiasis)

Achalasia…..

Apristalsism Lack or decreased LES relaxation Esophageal rest hypertonisity Pre stenotic dilatation&muscle

hypertrophy Dysphagia,regorgitation,aspiration SCC 5% in younger patient

Oesophageal varices

Localised dilatation of lower oesophageal veins

Secondary to portal hypertension (portal vein thrombosis or hepatic cirrhosis)

Haemorrhage can be catastrophic

Mallory weiss syndrome

Longitudinal tearing in GE junction

Hyperemesis Hematemesis Superficial or

deep

Mediastinitis No sequela

Inflammation (oesophagitis)

Acute infective – Herpes virus, Candida. Both seen most commonly in immunosuppressed.

Ingestion of corrosives Chronic reflux through lower

oesophageal sphincter(most common) Uremia,chemotherapy,radiation Sliding hiatal hernia

Herpes oesophagitis

Punched-out ulcers Viral intranuclear inclusions Formation of multinucleated giant cells

(cytopathic effect)

Herpes oesophagitis

Candida oesophagitis

Haemorrhagic mucosa with white plaques

Fungal hyphae and yeast forms on microscopy

Reflux oesophagitis

Common – often without symptoms Mucosa exposed to acid-pepsin and bile Increased cell loss and regenerative activity

Consequences of reflux oesophagitis

Ulceration Stricture Glandular

metaplasia (Barrett’s oesophagus)

Carcinoma

Barrett’s oesophagus

Columnar epithelial cells in lower oesophagus

Variable extent Presence of goblet

cells “intestinal metaplasia” associated with risk of progression to dysplasia/cancer 30-40 X

Oesophageal neoplasms

Benign tumours (rare): squamous papilloma, leiomyoma

Malignant tumours Squamous carcinoma Adenocarcinoma

Presenting symptom - dysphagia

Epidemiology of oesophageal cancer

Squamous carcinoma commonest worldwide 1-2% all cancer death

Adenocarcinoma has very different risk factors and is now the commonest type in Europe/N.America

Scc >90% in other parts In US 50%

Squamous carcinoma

High incidence in Southern Africa (incl. Malawi), China, Iran

Probably diet related (A and B vitamin deficiency, fungal contamination) – tobacco and alcohol also risk factors

Associated with chronic non-specific oesophagitis

Gross morphology

Fungative masses penetrating ulceration Infiltration into the eso.wall

Squamous carcinoma

Often large exophytic occluding tumours

Invasive disease preceded by dysplasia and carcinoma in situ

Adenocarcinoma

Occurs in lower oesophagus

Often associated with Barrett’s oesophagus (progresses through dysplasia to cancer)

Clinical course of oesophageal cancer

Grim! (even with best available resource)

Tumours have commonly spread to regional nodes and/or liver at presentation

No peritoneal lining in mediastinum – local invasion (heart, trachea, aorta) often limits surgery

Any question?