Histopathology: gastritis and peptic ulceration

Transcription

1 Histopathology: gastritis and peptic ulceration These presentations are to help you identify, and to test yourself on identifying, basic histopathological features. They do not contain the additional factual information that you need to learn about these topics, or necessarily all the images from resource sessions. This presentation contains images of basic histopathological features of Helicobacter gastritis, peptic ulceration and gastric adenocarcinoma. Before viewing this presentation you are advised to review relevant histology, relevant sections in a pathology textbook, relevant lecture notes, relevant sections of a histopathology atlas and the histopathology power point presentations on inflammation. Copyright University of Adelaide 2011 Med 1 students should have an understanding of Helicobacter gastritis and peptic ulceration (semester 2)

2 Helicobacter pylori causes an active chronic gastritis (image). The active or activity refers to the presence of acute inflammation in addition to chronic inflammation. Neutrophils are present in the lamina propria of the mucosa and infiltrate the epithelium (black arrows). It is difficult to appreciate that these are neutrophils at this magnification. The image shows excessive numbers of chronic inflammatory cells in the lamina propria (black stars) indicating chronic inflammation.

3 Active chronic gastritis with intestinal metaplasia as seen with Helicobacter pylori. Goblet cells (black arrows) are not normally seen in the gastric epithelium. Their presence here represents intestinal metaplasia. This change occurs as a result of the effects of H. pylori. It can also occur in autoimmune gastritis. There are too many chronic inflammatory cells in the lamina propria (black stars) indicating chronic inflammation.

4 Helicobacter

5 M Very low power view of a chronic peptic ulcer of the stomach. This one only penetrates into submucosa. There are classically several layers in the base of a chronic peptic ulcer: a) necrotic slough and acute inflammatory exudate (yellow star) b) granulation tissue (red star) c) scar tissue (blue stars) Patchy aggregates of lymphocytes (seen as dark areas/tiny dark dots due to their high N:C ratio on this low power) are also noted around the ulcer (black arrows). Make sure you can identify the layers of the wall. M: mucosa SM: submucosa MP: muscularis propria S: serosa Ulcer crater MP SM S SM MP

6 M SM MP Very low power view of the edge of a chronic peptic ulcer of the stomach. This one penetrates through muscularis propria into serosa. Black star: ulcer floor. M: mucosa SM: submucosa MP: muscularis propria

7 Chronic gastric ulcer. High power view of floor of ulcer. Black star: necrotic tissue Yellow star: oedematous vascular granulation tissue.

8 Chronic gastric ulcer. High power view of vascular granulation tissue in floor of ulcer. Black arrows: capillaries Yellow stars: macrophages, lymphocytes and plasma cells.

9 Gastric biopsies. Endoscopy (upper and lower GI) is a very common investigation. Biopsies are frequently taken from lesions or abnormal areas of mucosa. Such endoscopic biopsies are from 1-3mm in diameter and comprise mucosa +/- a tiny bit of submucosa.

10 A B Helicobacter pylori predisposes to the intestinal type of adenocarcinoma of the stomach, the cells of which form glands (black arrows, image A) and is thought to develop as result of intestinal metaplasia and dysplasia in chronic gastritis. Macroscopically these tumours form localised ulcerated lesions. The other main type of adenocarcinoma of the stomach is the signet ring type (image B) which typically more diffusely infiltrates the stomach wall. The tumour cells contain mucin which pushes the nucleus to one side, the overall effect resembling a signet ring (yellow arrows, image B).