Page 409 - Concise Pathology for Exam Preparation ( PDFDrive )

394
394 SECTION II Diseases of Organ Systems
Pathogenesis (Flowchart 14.1)

Prolonged recurrent GE reflux

Inflammation and ulceration of squamous epithelial lining of
the lower segment of oesophagus

Re-epithelialization and in growth of pluripotent stem cells
Squamous epithelium replaced by
metaplastic columnar epithelium of the
intestinal type (columnar epithelium shows
a greater resistance to acid injury than
squamous epithelium)
In an environment of sustained low pH, these cells may become dysplastic (0.2–2% patients)
Dysplasia

Low grade High grade
Adenocarcinoma
(may involve, adjacent cardiac end of stomach)
FLOWCHART 14.1. Pathogenesis and consequences of Barett’s oesophagus.

Gross Morphology
Red and velvety mucosa with raised patches, which later form large nodular masses with
infiltrative or ulcerative features.

Microscopy

• Most important complication is the development of adenocarcinoma (30–40 folds in-
creased risk).
• Most tumours are mucin-producing glandular tumours.
• Occasional development of SCC, adenosquamous or adenocarcinoid tumours supports
the concept that Barrett’s epithelium arises from pluripotent cells.

Q. Write briefly on carcinoma oesophagus.

Ans. Age group affected in carcinoma oesophagus is more than 50 years; males are more
commonly affected than females.

Predisposing Conditions/Factors
1. Adenocarcinoma: Incidence is on the rise in western countries due to rampant obesity
which in turn is responsible for increasing the incidence of GERD and Barrett mucosa.
2. Squamous cell carcinoma: Most common type worldwide. Predisposing factors
include
(a) Achalasia
(b) Plummer–Vinson syndrome
(c) Strictures, diverticulae and webs
(d) Alcohol, hot and spicy foods, betel chewing, smoking, aflatoxins and silica
(e) Diet deficient in vitamins A, C and trace elements
(f ) Diet high in nitrosamines

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