|Path Labs||CTools||Lab Instructors||ImageScope||Histology Normals||Histology Site||M1 Histopathology|
GI Path Lab 1
Reading Assignments (Robbins: Pathologic Basis of Disease, 8th Ed.)
|768 - 772||Esophagitis and Barrett's|
|772 - 774||Malignant tumors. The relative frequencies of squamous cell and adenocarcinomas are changing. In western societies, adenocarcinomas are now more common and squamous cell carcinomas less common.|
|774 - 776||Acute gastritis and acute gastric erosions: the discussions on pages 796-797 describe different intensities of the same disease.|
|776 - 780||Chronic gastritis and peptic ulcer disease: Helicobacter pylori is associated with (actually causes) over 95% of duodenal peptic ulcers, and perhaps 70% of gastric peptic ulcers. The rest are usually secondary to use of NSAIDs.|
|784 - 790||Carcinoma of the stomach|
Areas of Concentration
Upon completion of this exercise, you should be able to:
Esophagus: Barrett’s Mucosa with Dysplasia
Some of the slides contain slightly inflamed gastric mucosa at one end. Extending from that all the way to the other end is a columnar mucosa that has scattered deep mucus-producing glands and superficial elongated tubules, some of which extend from the surface to the base of the mucosa. Some of these tubules are lined by gastric-type surface epithelium with apical pink mucous vacuoles. Other tubules have intestinal-type goblet cells with big blobs of blue-staining mucus, evidence of intestinal metaplasia. Still other tubules have very little mucus of any type and contain epithelium with large, stratified nuclei which, in a few areas, are hyperchromatic and even vary in size and shape. These latter features are those of dysplasia.
Squamous Cell Carcinoma of the Tongue (to be used as a surrogate for squamous cell carcinoma of the esophagus; pretend that this is the esophagus!)
This squamous cell carcinoma of the esophagus invades deeply, has a variety of patterns and is present in dilated spaces that are lymphatics.
Chronic Active Gastritis - Helicobacter pylori Type
The normal gastric mucosa has very few inflammatory cells. This mucosa, in contrast, is intensely inflamed. First, there are many lymphoid nodules at the base of the mucosa, some with hyperplastic germinal centers. Second, there is intense plasmacytosis in the superficial part of the mucosa, in the region of the pits and the superficial glands. In fact, some patches of lamina propria are stuffed with plasma cells. Finally, in some of the sections, there are a few neutrophils within the epithelium of the neck regions and in the surrounding lamina propria. This gastritis is typical of the type caused by H. pylori. We rarely see the organisms in a resected specimen such as this, perhaps as a result of treatment with antibiotics prior to the operation, or because in resection specimens the pathologist tends to wash the mucosa in order to see it better, and washing removes the mucus coat in which the organisms usually reside.
Stomach: Peptic Ulcer
The ulcer is the broad area that has no mucosa.
Stomach: Early Gastric Carcinoma
This is gastric mucosa in which the mucus glands take up approximately half of the entire thickness, indicating that it is either antral or cardiac mucosa. In some sections, at one end, there is a peculiar mucosa with villous-like surface projections and goblet cells with bluish mucus scattered among the more typical gastric surface cells that contain apical pink-staining mucus. This is intestinal metaplasia, one of the histologic changes in atrophic gastritis. It resembles the Barrett's mucosa of Slide 84. In fact, it has similar dysplastic changes.
In the center of the slide, the epithelium becomes more disorganized with hyperchromatic and pleomorphic nuclei and numerous mitotic figures. At the base of the mucosa, this epithelium invades through the fibers of the muscularis mucosae. In some slides, nests of carcinoma are found within lymphatics in the superficial submucosa. The deeper submucosa, muscularis propria and subserosa of the wall of the stomach are normal.
The answers to the path lab questions will be posted approximately 48-72 hours after the lab sessions. These are abbreviated answers, not a full discussion of the topics. You can find them in the M2 CTools site resources. In the folder for each sequence the will be a folder called 'Path Lab Resources'