Summary pathology part 2
Lecture 6, gastrointestinal tract
Normal esophagus
Darker pink: stomach
Z-line: divide stomach and oesophagus caused by different epithelium
Layers esophagus from inside to outside: (important to locate tumours etc.)
Mucosa:
• squamous epithelium
• lamina propria: fibroblasts and small amount of lymphocytes
• Muscularis Mucosa
Submucosa: Fatty tissue, fibroblasts and vascular structures
Circular smooth muscle layer
Longitudinal smooth muscle layer
Adventitia: fatty tissue
,Development of oesophageal carcinoma
(precursor lesion become before the tumour exists: oesophagitis OR dysplasia)
Adenocarcinomas are more common, they can occur in the esophagus because of intestinal
metaplasia where the squamous epithelium is replaced by columnar epithelium.
(long-term esophagitis) Reflux oesophagitis
• Phase 1: Inflammation
Hyperemia, granulocytes and in severe cases ulceration
Occurs when the content of the stomach, which is very acidic
goes up into the oesophagus. The squamous epithelium in the oesophagus is not made to
deal with that. The squamous epithelium will have inflammation: neutrophil recruitment etc.
When reflux esophagitis keeps existing intestinal metaplasia
Reflux oesophagitis
• Phase 2: Metaplasia and (chronic) inflammation
– metaplasia: replacement of a differentiated cell type by another differentiated cell type
,Intestinal metaplasia
Squamous epithelium is replaced by intestinal-type epithelium (= intestinal metaplasia)
Barrett oesophagus (=intestinal metaplasia)
The Z-line is not as straight anymore and in addition, it is not pink but more because of
inflammation. The histology picture shows cylindrical cells.
When inflammation keeps on continuing: Dysplasia of intestinal-type epithelium
Molecular changes go along with morphological changes. Cytoplasm reduced. We call it
Atypia because it is associated with molecular changes and genetics changes. It really
increases your risk for adenocarcinoma.
, Adenocarcinoma of the oesophagus (=Barrett carcinoma)
Invading the muscular propria.
The main difference between dysplasia and adenocarcinoma is that in dysplasia the cells
have changes and mutations but the cells are still located in the area where they are
supposed to be. When they start invading, we call it adenocarcinoma.
Adenocarcinoma of the oesophagus
Dysplastic glands on top, irregular glands deeper in the tissue.
Lecture 6, gastrointestinal tract
Normal esophagus
Darker pink: stomach
Z-line: divide stomach and oesophagus caused by different epithelium
Layers esophagus from inside to outside: (important to locate tumours etc.)
Mucosa:
• squamous epithelium
• lamina propria: fibroblasts and small amount of lymphocytes
• Muscularis Mucosa
Submucosa: Fatty tissue, fibroblasts and vascular structures
Circular smooth muscle layer
Longitudinal smooth muscle layer
Adventitia: fatty tissue
,Development of oesophageal carcinoma
(precursor lesion become before the tumour exists: oesophagitis OR dysplasia)
Adenocarcinomas are more common, they can occur in the esophagus because of intestinal
metaplasia where the squamous epithelium is replaced by columnar epithelium.
(long-term esophagitis) Reflux oesophagitis
• Phase 1: Inflammation
Hyperemia, granulocytes and in severe cases ulceration
Occurs when the content of the stomach, which is very acidic
goes up into the oesophagus. The squamous epithelium in the oesophagus is not made to
deal with that. The squamous epithelium will have inflammation: neutrophil recruitment etc.
When reflux esophagitis keeps existing intestinal metaplasia
Reflux oesophagitis
• Phase 2: Metaplasia and (chronic) inflammation
– metaplasia: replacement of a differentiated cell type by another differentiated cell type
,Intestinal metaplasia
Squamous epithelium is replaced by intestinal-type epithelium (= intestinal metaplasia)
Barrett oesophagus (=intestinal metaplasia)
The Z-line is not as straight anymore and in addition, it is not pink but more because of
inflammation. The histology picture shows cylindrical cells.
When inflammation keeps on continuing: Dysplasia of intestinal-type epithelium
Molecular changes go along with morphological changes. Cytoplasm reduced. We call it
Atypia because it is associated with molecular changes and genetics changes. It really
increases your risk for adenocarcinoma.
, Adenocarcinoma of the oesophagus (=Barrett carcinoma)
Invading the muscular propria.
The main difference between dysplasia and adenocarcinoma is that in dysplasia the cells
have changes and mutations but the cells are still located in the area where they are
supposed to be. When they start invading, we call it adenocarcinoma.
Adenocarcinoma of the oesophagus
Dysplastic glands on top, irregular glands deeper in the tissue.
