Pathology GI tract Flashcards Preview

September lectures yr 3 (2018) > Pathology GI tract > Flashcards

Flashcards in Pathology GI tract Deck (59)
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1
Q

When does esophagitis commonly occur?

A

reflux of gastric contents with inflammation being reactive to chemical damage from acid or bile

2
Q

What does histology show in esophagitis?

A

infiltrates of neutrophils and hyperplasia of the basal epithelial cells

3
Q

What can happen in more severe cases of esophagitis?

A

ulceration

4
Q

Other than reflux what else can cause esophagitis?

A

candida infection and viral infections (herpes simplex, cytomegalovirus) in immunosuppressed
Acute inflammation can be caused by swallowing caustic chemicals
and chronic granulomatous CD can affect oesophagus

5
Q

What can long standing esophagitis lead to ?

A

metaplasia of the normal squamous epithelium lining the oesophagus into glandular mucosa in which epithelium shows a mixture of gastric (columnar mucous containing cells) and intestinal type epithelial cells (goblet cells and absorptive cells)

6
Q

What is the metaplasia known as in esophagitis?

A

barrett’s esophagitis - can progress to dysplasia and then to adenocarcinoma

7
Q

What is achalasia?

A

muscles of the lower part of the oesophagus fail to relax, preventing food entering the stomach
Failure of the gastro-esophageal sphincter when swallowing

8
Q

What happens distal to the gastro-esophageal sphincter in achalasia?

A

dilates distal to the sphincter and mucosa becomes inflamed and thickened
- risk of malignant tumors developing

9
Q

What are esophageal varices?

A

dilated veins that develop in the lower oesophagus due to portal vein hypertension

10
Q

What are the most common types of tumors in the oesophagus?

A

most are carcinomas - benign ones are rare
- squamous cell carcinoma are the most common in the upper and middle oesophagus = typically preceded by pre-malignant dysplasia in the squamous epithelium

11
Q

Where do adenocarcinomas develop in the oesophagus?

A

in the lower oesophagus

12
Q

What information needs to be included in a pathology report of a resected tumor?

A

tumor type
grade of differentiation
depth of tumor invasion
presence or absence of vascular invasion
relationship of tumor to the surgical margins,
number of lymph nodes and total number of nodes in the specimen

13
Q

What does pT1, pT2, pT3 and pT4 stand for in terms of esophageal tumor?

A

1 - limited to the mucosa or submucosa
2- extending into but not through the muscular properia
3- invasion into the peri-oesophageal adventitia
4- invasion into adjacent pleura, pericardium or other organs

14
Q

How does nodal staging with esophageal work?

A

n=0 = none
n=1 = 1-2 local lymph nodes
n=2= 3-6 nodes
n=3 - >6 nodes

15
Q

What is the commonest cause of gastritis?

A

infection with the spiral bacterium helicobacter pylori

16
Q

What is the histology of helicobacter pylori infection?

A

acute on chronic inflammatory cell infiltrate

17
Q

What happens over time with helicobacter pylori induced gastritis?

A

atrophy of the specialized mucosal glands and metaplasia of the epithelium into an intestinal type in which goblet cells (cells with the cytoplasm distended by mucin) are visible

18
Q

What can long standing inflammation in gastritis cause?

A

complicated by dysplasia which is associated with a high risk of malignant progression

19
Q

What are some other causes of gastritis?

A

autoimmune and reactive (due to chemical damage such as bile reflux or NSAIDs)
Stomach can also be affected in CD
And rarely in coeliac disease the stomach can show inflammation known as lymphocytic gastritis

20
Q

What can complicated chronic gastritis?

A

chronic ulcers or may be malignant

21
Q

What are the commonest stomach polyps?

A

regenerative or hyperplastic in nature and have NO association with malignant

22
Q

What other types of polyps can arise in the stomach?

A

adenomas - rare but high risk of malignant progression
hamartomatous polyps with distinctive histological appearance - many are features of specific syndromes e.f. peutz-jeghers

23
Q

What are most neoplasms of the stomach ?

A

malignant adenocarcinomas - may be polypoid, ulcerated or diffusely infiltrative
- diffusely infiltrative ones may diffusely thicken the stomach wall without any focal lesion being seen

24
Q

What are the different microscopic appearances of stomach tumors?

A

intestinal - resemble tumors found in the large intestine
diffuse - tumor cells diffusely invade singly and in small groups through the stomach wall
mucin secreting
solid undifferentiated tumors

25
Q

What does pT1, pT2, pT3 and pT4a and pT4b stand for in terms of stomach tumor?

A
1- confined to the mucosa or submucosa
2- invasion into the muscular propria
3- invasion into the subserosa
4a- invasion onto the peritoneal surface
4b- invasion into adjacent organs e.g. liver or pancreas
26
Q

What is the prognosis for pT1 tumors?

A

regardless of pN stage has excellent prognosis and is often called early gastric carcinoma

27
Q

What do gastric lymphomas usually arise from?

A

usually primary to the stomach where they arise from mucosa associated lymphoid tissue and are strongly associated with H.pylori infection - low grade tumors will regress if H.pylori is eradicated by ABX

28
Q

What is GIST and what it is composed of?

A

gastro-intestinal stromal tumours - composed of spindle cells that express CD117 which is a receptor tyrosine kinase that can be directly inhibited and therefore advanced or metastatic tumors can be treated

29
Q

What is duodenitis most commonly caused by?

A

excess gastric acid secretion as found in early H.Pylori - can be complicated by ulceration in the first part of the duodenum

30
Q

On histology what does duodenitis look like?

A

active inflammation and metaplasia into a gastric type epithelium

31
Q

What is coeliac disease characterized by?

A

loss of vili, elongation of crypts and an increase in the number of intra-epithelial lymphocytes - changes revert back o normal on a gluten free diet

32
Q

What is whipples disease?

A

Malabsorptive disorder

- accumulation of foamy macrophages in the lamina propria which contain the causative bacteria

33
Q

What is giardia infection?

A

malabsorptive disorder caused by a flagellate protozoan

34
Q

What is crohns disease?

A

chronic inflammatory process affecting one or several segments of the GIT = most common site is terminal ileum
Patchy ulceration in the mucosa giving a cobblestone appearance
- inflammation and fibrosis is transmural
- inflammatory infiltrate includes the formation of granulomas

35
Q

What can cause small bowel infarctions?

A

through the full thickness of the bowel wall is caused by thrombus or embolus in the mesenteric arteries, torsion or intussusception leading to compression of the venous circulation or compaction in a hernia

36
Q

What is the mucosa type in meckel’s diverticulum?

A

mucosa is sometimes of gastric type - any pathology of the stomach mucosa can occurs in these diverticula (small bowel)

37
Q

What are the commonest tumors of the small bowel?

A

lymphomas and carcinoid tumors - both are often multiple at presentation

38
Q

What are carcinoid tumors of the small bowel like?

A

low grade malignant tumors showing an endocrine pattern of cell differentiation

39
Q

What are lymphomas of the small bowel like?

A

many are primary and of MALT, immune proliferative small intestine disease (B cell) and enteropathy associated T cell lymphoma which may complicate coeliac disease

40
Q

Can adenomas occur in the small bowel?

A

rare except at the ampulla in the duodenum where they may derive from the duodenal mucosa, the pancreas of bile duct

41
Q

What happens in acute appendicitis?

A

appendix becomes swollen, congested and covered by a fibrinous exudate

42
Q

On histology what can be seen in an acute appendicitis?

A

mucosal ulceration, transmural active inflammation extending into the peritoneal surface and in severe cases necrosis of the wall

43
Q

Where do appendiceceal carcinoid tumors occurs and what are they like?

A

occur at the tip of the appendix (usually incidental finding)
tumors are infiltrative, but they rarely spread beyond the appendix or metastasize

44
Q

What can acute and sub-acute infective colitis be caused by?

A

bacteria, some protozoa (amoebae), some viruses and TB

- pseudomembranous colitis results from ischemic damage to the mucosa from clostridium difficile toxin

45
Q

What happens in subacute ischemic colitis?

A

affects the splenic flexure and shows ulceration with inflammation in the mucosa, submucosal vascular proliferation and fibrosis

46
Q

What happens in microscopic colitis?

A

thickening of the basement membrane of the surface epithelium (collagenous colitis) and/or increased intra-epithelial lymphocytes (lymphocytic colitis)

47
Q

What can be seen in both UC and CD?

A

mucosal ulceration and an acute on chronic inflammatory cell infiltrate with disordered crypt architecture

48
Q

How are UC and CD different in terms of their effects?

A

UC the inflammation affects a continuous segment extending proximally from the rectum and inflammation is limited to the mucosa

In CD inflammation is patchy and discontinuous (skip lesions), affect all layers of the bowel with fibrosis, individual crypt destruction and inflammation include granulomas

49
Q

What are diverticula?

A

mucosal herniations through the muscular propria - prone to hemorrhage, infection and perforation

50
Q

What is angiodysplasia?

A

composed of dilated thin walled blood vessels in the submucosa and mucosa and are prone to hemorrhage - difficult to demonstrate in a resected specimen

51
Q

What are the commonest type of polyp in the colon?

A

hyperplastic polyps - increased cellularity of crypts with a heaped up epithelium

52
Q

What other polyps can occur in the colon?

A

non-neoplastic polyps = juvenile, hamartomatous and inflammatory

53
Q

What are adenomas in the colon like?

A

usually polypoid on a stalk but may be sessile or flat

Architecture can be glandular (tubular adenoma), papillary (villous adenoma) or both (tubullo-villous adenoma)

54
Q

What is the issue with adenomas?

A

risk of malignant progression - especially if large and villous

55
Q

What is FAP?

A

Familial adenomas polyposis coli - dominantly inherited predisposition to develop multiple adenomas by the third decade of life, very high risk of malignancy due to large numbers of adenomas

56
Q

What tumors can arise in the colon?

A

most are adenocarcinomas

also get carcinoids, lymphomas and GISTs

57
Q

What does pT1, pT2, pT3 and pT4 stand for in terms of colon tumor?

A

1 - confined to the submucosa
2- invasion into but not through muscular propria
3- invasion into the subserosa
4- invasion onto the peritoneal surface or adjacent organs

58
Q

What is the minimum information required for categorizing a colon tumor?

A

site of tumor, maximum tumor diameter, presence or absence of tumor at the resection ends and distance to nearest resection end, histological type, grade, depth of invasion, presence or absence of vascular invasion, number of lymph nodes present and the number of nodes involved

59
Q

What additional information is required for rectal tumors?

A

relationship of the tumor to there peritoneal reflection, distance to the dentate line and the distance to the radial (mesorectal) margin should be described

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