Page 408 - Concise Pathology for Exam Preparation ( PDFDrive )

14 The Oral Cavity and Gastrointestinal Tract 393

Aetiology

• Primary achalasia: Aetiology unknown (may be neuronal rather than a myopathic
disorder). Number of ganglion cells have been found to be decreased in Auerbach’s
plexus (ganglion cell degeneration).
• Secondary forms: Typically seen in Chagas disease (Trypanosoma cruzi infection), polio,
diabetic autonomic neuropathy, infiltrative disorders, eg, malignancy, amyloidosis and sar-
coidosis. Coexistence with other autoimmune diseases like Sjogren syndrome or thyroiditis
indicates that there may be immune-mediated destruction of inhibitory oesophageal neurons.

Microscopy
Oesophageal wall is thickened in the distal portion (there is smooth muscle hypertrophy,
particularly of inner circular layer); proximal dilated segment is actually thinned out.

Q. Write briefly on gastroesophageal reflux disease (GERD).
Ans. GERD is a chronic diffuse erosive/ulcerative oesophagitis. Normally the oesophageal
lining is protected from acids by
1. The abundant submucosal glands in proximal and distal oesophagus (which secrete
mucin and bicarbonate)
2. The tone of LES which prevents reflux of acidic gastric contents
Pathogenesis

Both genetic and environmental factors contribute to cause decreased LES pressure which
allows reflux.

Predisposing Factors
Pregnancy, ascites, obesity, delayed gastric emptying and peristaltic disorders, eg, scleroderma
Clinical Features

Heartburn, regurgitation, dysphagia/odynophagia, water brash (hypersalivation) and a
typical intermittent chest pain
Complications

Ulceration, haematemesis, melena, stricture formation and Barret oesophagus

Diagnosis
X-ray and endoscopy

Pathology
• One-third patients have a normal appearing mucosa. Erythema and red streaks are ear-
liest markers of disease followed by erosions and ulcers.
• There may be contact bleeding with endoscope indicating increased friability.
• Dilated vessels and inflammatory cells are present.
• Predominance of eosinophils points to a diagnosis of ‘eosinophilic esophagitis’
which is seen in patients with atopy with coexisting atopic dermatitis, rhinitis,
asthma and eosinophilia. These patients present with dysphagia and symptoms of
food impaction.

Q. Write briefly on Barrett’s oesophagus.
Ans. Barrett’s oesophagus is a complication of long-standing GE reflux. It is seen between
40 and 60 years of age Males are more commonly affected than females. Hallmark is re-
placement of distal squamous mucosa by metaplastic columnar epithelium as a response
to prolonged injury.

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