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Flashcards in Pathology Deck (132):
1

What is a polyp?

A protrusion above an epithelial surface

2

Classify the vast amount of polyps in the large bowel

Benign, epithelial and neoplastic

3

Differential diagnosis of a colonic polyp

Adenoma
Serrated polyp
Polypoid carcinoma
Other

4

Three macroscopic appearances of removed colonic polyps

Pedunculated
Sessile
Flat

5

Explain adenoma of the colon

Benign tumours of the colon. Not yet invasive, and do not metastasise. All dysplastic = must be removed

6

Adenoma-Carcinoma Sequence

Normal epithelium -> mutations to APC -> small adenoma -> further mutation e.g. k-ras -> large adenoma -> chromosomal mutations e.g. p53 -> Invasive adenocarcinoma

7

Why remove all adenomas?

They are premalignant

8

Removal of adenomas by...?

Endoscopy
Surgery

9

Primary treatment of Adenocarcinoma

Surgical removal of colon/rectum for staging

10

What kind of tumours are majorly found in the large bowel?

Malignant Adenocarcinomas

11

Colorectal Carcinoma - Dukes Staging

Dukes A = Confined by muscular propria
Dukes B = Through muscular propria
Dukes C = Metastatic to lymph nodes

12

Left Sided Colorectal Carcinoma

75%
P/R Bleeding
Altered Bowel Habit
Obstruction

13

Right Sided Colorectal Carcinoma

25%
Anaemia
Weight Loss

14

Colorectal carcinoma - Gross appearance

Varied =
Polypoid
Stricturing
Ulcerating

15

Colorectal carcinoma - Histopathological appearance

Typical adenocarcinoma

16

Colorectal carcinoma - Local invasion

Mesorectum, peritoneum, other organs

17

Colorectal carcinoma - Lymphatic spread

Mesenteric nodes

18

Colorectal carcinoma - Haematogenous spread

Liver, distant sites

19

Inherited Colorectal Carcinoma - HNPCC

Late onset (50/60s)

20

Inherited Colorectal Carcinoma - FAP

Early onset (teens)
>100 polyps
Mutation to FAP gene
Tumours throughout colon
Adenocarcinoma NOS
Desmoid tumours & thyroid carcinomas

21

Diverticular Disease - Histopathology

Out-pouchings of mucosa
These are at increased risk of bursting and releasing septic contents into the abdominal cavity

22

Diverticular Disease - Complications

Inflammation
Rupture
Abscess
Fistula
Massive Bleeding

23

Ischaemia of the Large Bowel - Endoscopic View

Diffusely ulcerated and erythematous mucosa

24

Ischaemia of the Large Bowel - Histopathology

Withering of crypts
Smudging of lamina propria
Fewer chronic inflammatory cells

25

Ischaemia of the Large Bowel - Aetiology

CVS disease, A Fib, Embolus, Atherosclerosis (usually IMA), Shock, Vasculitis

26

Ischaemia of the Large Bowel - Clinical Context

Elderly
Left sided
Segmental on endoscopy

27

Ischaemia of the Large Bowel - Complications

Massive Bleeding
Rupture
Stricture

28

Antibiotic-Induced "Pseudomembranous" Colitis - Endoscopic View and Gross Appearance

Speckled, spotted appearance
Patchy, yellow membranous exudate on mucosal surface

29

Antibiotic-Induced "Pseudomembranous" Colitis - Histopathology

Explosive fibrinopurulent exudate on surface (volcano lesions)

30

Antibiotic-Induced "Pseudomembranous" Colitis - Causes

Patients in broad spectrum of antibiotics - C Diff proliferates
Toxins A and B attack endothelium and epithelium, causing mini-infarcts along the membrane

31

Antibiotic-Induced "Pseudomembranous" Colitis - Symptoms

Massive diarrhoea and bleeding

32

Antibiotic-Induced "Pseudomembranous" Colitis - Treatment

Flagyl/Vancomycin
May need colectomy
May be fatal

33

Collagenous Colitis - Appearance

Endoscope = Normal
Histology = Increase in thickness of sub epithelial collagen

34

Collagenous Colitis - Clinically

Watery diarrhoea
Normal endoscopy
History of causative drugs

35

Lymphocytic Colitis - Appearance

Endoscope = Normal
Histology = Normal architecture, but massive increase in intraepithelial lymphocytes

36

Lymphocytic Colitis - Clinically

Watery diarrhoea
Normal endoscopy
Raise possibility of Coeliac disease

37

Radiation Colitis - Endoscopy Appearance

Red, angry bowel

38

Radiation Colitis - Histology

Bizarre stream cells
Bizzarre vessels

39

Radiation Colitis - Cause

History of cervical/prostate cancer
Radiation therapy damaged cells

40

Acute (infective) Colitis _ Endoscopy Appearance

Very red
Very ulcerated
Very inflamed

41

Acute (infective) Colitis - Histology

Busy epithelium but not crypt irregularity
Florid diffuse acute cryptitis

42

Acute (infective) Colitis - Causes

Infection
Rarely: Drugs, ischaemia, endoscopy prep.

43

Acute (infective) Colitis - Diagnosis

Stool sample culture

44

Normal Appearance of the Liver

Light, tan in colour
Smooth regular surface

45

Pathogenesis of Liver Disease

Insult to hepatocytes
Inflammation
Fibrosis
Cirrhosis

46

Causes of Acute Onset of Jaundice

Viruses
Alcohol
Drugs
Bile duct obstruction

47

Histological Appearance of Paracetamol Poisoning

Confluent necrosis produce massive acute necrosis and liver failure
(lots of hepatocyte death)

48

Consequences of Acute Liver Failure

Complete recovery
Chronic liver disease
Death from liver failure

49

Pre-Hepatic Jaundice

Too much harm to break down
Haemolysis of any cause
Haemolytic anaemias
Unconjugated billrubin

50

Hepatic Jaundice

Liver cells injured or dead
Acute liver failure
Alcoholic hepatitis
Cirrhosis (decompensated)
Bile duct loss
Pregnancy
Conjugated jaundice

51

Post-Hepatic Jaundice

Biel cannot escape into the bowel
Congenital biliary atresia
Gallstones blocking CBD
Strictures of CBD
Tumours

52

Appearance of a Cirrhotic Liver

Nodular, craggy, scarred

53

Histological Appearance of Cirrhosis

Bands of fibrosis separating regenerative nodules of hepatocytes
Loss of function of hepatocytes due to alteration of hepatic microvasculature

54

Complications of Cirrhosis

Portal hypertension =
Oesophageal varices
Caput medusa
Rectal varices

Ascites

Liver Failure

55

Alcoholic Liver Disease - Pathology Influenced By

Extent of the alcohol abuse
Individual factors

56

Pathogenesis of Alcoholic Liver Disease

Increased peripheral release of fatty acids
Increased synthesis of fatty acids within the liver cells
Acetaldehyde, a product of alcohol metabolism, is probably responsible for liver cell injury (manifested by the formation of Mallory's hyalin)
Increased collagen synthesis by fibroblasts

57

Appearance of Alcoholic Fatty Liver - Days

Yellow
Greasy

58

Histological Appearance of Alcoholic Fatty Liver - Days

Fat vacuoles appear clear in hepatocytes

59

Histological Appearance of Alcoholic Fatty Liver - Heavy Drinking Weeks to Months

Accumulation of bile
Hepatocytes with thick dark pink cytoplasm
Accumulation of neutrophils

60

Histological Appearance of Alcoholic Fatty Liver - Heavy Drinking Months to Years

Collagen played down around cells
Collagen appears blue

61

Appearance of Alcoholic Cirrhosis

Micro-nodular cirrhosis with abundant white scarring

62

Histological Appearance of Alcoholic Cirrhosis

Bands of fibrosis separating regenerative nodules

63

Alcoholic Liver Disease - Outcome

Cirrhosis
Portal hypertension
Malnutrition
Hepatocellular carcinoma
Social disintegration

64

Non-Alcoholic Steatohepatitis

Non-drinkers
Pathologically identical to alcoholic liver disease
Occurs in patients with diabetes, obesity, hyperlipidaemia
May lead to fibrosis and cirrhosis
Increasing incidence

65

Common causes of viral hepatitis

Hep A, B, C, E

66

Rarer causes of viral hepatitis

Hep D
Epstein-Barr virus
Yellow fever virus
Herpes Simplex virus
Cytomegalovirus

67

Hepatitis A - Histological Appearance

Death of hepatocytes
Directly cytopathic
No immunological phase

68

Chronic Viral Hepatitis -Histological Appearance

Visible immune cells are damaging the liver
Dense portal chronic inflammation (erodes the border)
Interface hepatitis (piecemeal necrosis)
Fibrosis forms bridges between different portal areas (bridges filled with collagen)
Cirrhosis
Not distinguishable from other chronic hepatitis causes

69

Hepatits B - Outcomes

Fulminant acute infection (death)
Chronic hepatitis
Cirrhosis
Hepatocellular carcinoma
Asymptomatic (carrier)

70

Hepatitis C - Outcomes

Chronic hepatitis
Cirrhosis

71

Causes of Chronic Hepatitis

Viruses = Hep B and C

Drug induced

Autoimmune =
Primary biliary cirrhosis/cholangitis
Autoimmune hepatitis
Primary sclerosing cholangitis

72

Primary Biliary Cirrhosis - Aetiology and Clinical

Rare autoimmune disease, unknown aetiology
Associated with autoantibodies to mitochondria
Females (90%)
Biopsy is to stage disease or diagnose uncertain cases
Outcome is unpredictable

73

Primary Biliary Cirrhosis - Histological Appearance

Chronic portal inflammation
Inflamed bile ducts
Granulomas around bile ducts
Cirrhosis

74

Primary Biliary Cholangitis - Pathogenesis

If untreated, bile duct loss leads to cholestasis liver injury, inflammation, fibrosis and cirrhosis

75

Autoimmune Hepatitis - Clinical

Commoner in females
Associated with other AI
Chronic hepatitis pattern
May have triggers, including some drugs

76

Autoimmune Hepatitis - Histological Appearance

Numerous plasma cells
Autoantibodies to smooth muscle, nuclear or LKM
Raised IgG

77

Chronic Drug-Induced Hepatitis - Clinical

Similar features to all other types of chronic hepatitis
May trigger an autoimmune hepatitis
Chronic active process
Many causes

78

General Points about Drugs and the Liver

Innumerable drugs can damage the liver
May be dose related or idiosyncratic
Can cause hepatitis, granulomas, fibrosis, necrosis, failure, cholestasis or cirrhosis
Can mimic any liver disease

79

Primary Sclerosing Cholangitis - Clinical

Chronic inflammatory process affecting intra- and extra-hepatic bile ducts
Leads to pericardial fibrosis, duct destruction, jaundice and fibrosis
Associated with UC
More common in males
Increased risk of malignancy in bile ducts and colon

80

Primary Sclerosing Cholangitis - Histological Appearance

Periductal onion-skinning fibrosis
Loss/damage of bile ducts

81

Storage Disease - Types

Haemochromatosis
Wilsons Disease
Alpha-1-Antitrypsin Deficiency

82

What is haemochromatosis?

Excess iron within the liver

83

Primary Haemochromatosis - Causes

Genetic condition
Inherited autosomal recessive condition
Gene defect very complex
Exces absorption of iron from intestine, abnormal iron metabolism
Worse in homozygotes, men

84

Primary Haemochromatosis - Histological Appearance

Iron accumulates in hepatocytes
Iron confirmed by Perls Stain

85

Primary Haemochromatosis - Clinical

Iron deposited in liver, assymptomatic for years
Eventually deposited in portal connective tissue and stimulates fibrosis
Cirrhosis if not treated
Predisposes to carcinoma
Also causes diabetes, cardiac failure and impotence

86

Secondary Haemochromatosis - Causes

Iron overload from diet
Transfusions
Iron therapy

87

Haemochromatosis - Outcomes

Depends on genetics, therapy (venesection), cofactors like alcohol
Cirrhosis
Hepatocellular carcinoma

88

Wilson's Disease

Inherited autosomal recessive disorder of copper metabolism
Copper accumulates in liver and brain (basal ganglia)
Kayser-Fleischer rings at corneal limbus
Low serum caeruloplasmin
Causes chronic hepatitis and neurological deterioration

89

Alpha-1-Antitrypsin Deficiency

Inherited autosomal recessive disorder of production of an enzyme inhibitor
Causes empysema and cirrhosis
Cytoplasmic globules of unsecreted globules of protein in liver cells

90

Tumours of the Liver

Primary (rare)
Hepatocellular adenoma
Hepatocellular carcinoma (Hepatoma)

Secondary (common)
Multiple
Metastases from colon, pancreas, stomach, breast, lung and others

91

Hepatocellular Adenoma

Benign
Females
May become large - can rupture or bleed
Most remain asymptomatic

92

Hepatocellular Carcinoma

Rare in Europe
Associated with Hep B, Hep C, Cirrhosis, PBC, PSC
Usually presents as mass, pain, obstruction
usually advanced unless discovered incidentally
Poor prognosis

93

Hepatocellular Carcinoma - Histopathological Types

Hepatocyte = Malignant tumour of liver cells
Cholangio = Malignant tumour of bile ducts

94

What is Cholelithiasis?

Gallstones
Defined as hard stone-like or gravel-like material formed within the biliary system most commonly the gallbladder

95

What is normal bile made from?

Micelles of cholesterol, phospholipid, bile salts and bilirubin

96

Where is normal bile stored and how is it released?

Stored and concentrated in gallbladder, released by common cystic duct into the 2nd part of the duodenum through common bile duct and Ampulla of Vater

97

Pathogenesis of Cholesterol Gallstones

Gallstones form when there is an imbalance between the ratio of cholesterol to bile salts, disrupting micelle formation
Free crystallisation on micelle surface

98

Risk Factors for Cholesterol Gallstones

Cholesterol excess in bile
Female
Obesity
Diabetics
Genetic

99

Pathogenesis of Pigment Gallstones

Excess bilirubin cannot be solubilised in bile salts
Tend to be black

100

Risk Factors for Pigment Gallstones

Excess bilirubin
Due to excess haemolysis
e.g. Haemolytic anaemia

101

Pathogenesis of Gallstones

Gallbladder pH and mucosal glycoproteins may be contributory factors
Infection and inflammation of biliary lining
Most gallstones are a mixture (mixed stones)
Pure cholesterol and pure pigment stones do occur
Calcium carbonate stones do occur

102

Pathology of Gallstones

Acute Cholecystitis
Chronic Cholecystitis
Mucocoele
Empyema
Carcinoma
Ascending Cholangitis
Obstructive Jaundice
Gallstone Ileus
Acute Pancreatitis
Chronic Pancreatitis

103

What is cholecystitis?

Inflammation of gallbladder
Usually associated with gallstones
Acute or chronic
Common

104

Acute Cholecystitis

Gallstones obstructing outflow of bile
Initially sterile, then becomes infected
May cause empyema, rupture, peritonitis
Causes intense adhesions within 2-3 days

105

Acute Cholecystitis - Appearance

Gross = Red, haemorrhage, mixed gallstones embedded in pus
Histology = Acute inflammation indicated by neutrophils

106

Chronic Cholecystitis

Associated with Gallstones
May develop insidiously or after bouts of acute cholecystitis
Galbladder wall is thickened but not distended

107

Chronic Cholecystitis - Appearance

Gross = Mixed stones and thickened gallbladder wall due to fibrosis
Histology = Chronic inflammation and Rokitansky-Aschoff sinuses

108

What do stones in the common bile duct cause?

Obstructive jaundice

109

Carcinoma of the Gallbladder

Rare
Adenocarcinoma
Associated with gallstones
Local invasion of liver
Poor prognosis

110

Carcinoma of Bile Ducts (Cholangiocarcinoma)

Rare
Associated with Ulcerative Colitis and Primary Sclerosing Cholangitis
Presents with obstructive jaundice
Adenocarcinoma

111

What is a Klatskin Tumour?

Cholangiocarcinoma at bifurcation of hepatic ducts

112

Cholangiocarcinoma - Histology Appearance

Densely packed call glands in a fibrous stroma

113

What is Pancreatitis?

Inflammation of the pancreas
May be acute or chronic (overlap exists between the two)

114

Acute Pancreatitis - Clinical

Adults (rare in children)
Sudden onset severe abdominal pain
Patients may be severely shocked
Elevated serum amylase

115

Acute Pancreatitis - Aetiology

Alcohol
Cholelithiasis
Shock
Mumps
Hyperparathyroidism
Hypothermia
Trauma
Iatrogenic (post ERCP)

116

Acute Pancreatitis - Pathogenesis

Bile reflux, duct obstruction due to stone damage to sphincter of Oddi all cause pancreatic duct epithelial injury
Loss of protective barrier allows autodigestion of pancreatic acini
Release of lytic pancreatic enzymes proteases and lipases
Intra- and peripancreatic fat necrosis (lipases)
Tissue destruction and haemorrhage (proteases)

117

Appearance of Acute, Mild Pancreatitis

Focal areas of necrosis

118

Appearance of Acute, Moderate Pancreatitis

Intrapancreatic fat necrosis (may bind large amounts of calcium)

119

Appearance of Acute, Severe Pancreatitis

Complete pancreatic destruction with haemorrhage and fat necrosis

120

What is a Pancreatic Pseudocyst?

Fleshy pseudocyst complicating pancreatitis

121

Acute Pancreatitis - Histological Appearance

Large areas of pancreas and fat necrosis

122

Acute Pancreatitis - Complications

Death
Shock
Pseudocyst formation
Abscess formation
Hypocalcemia
Hyperglycaemia

123

What is Chronic Pancreatitis?

Relapsing disorder may develop insidiously or following bouts of acute pancreatitis

124

Chronic Pancreatitis - Aetiology

Alcohol
Cholelithiasis
Cystic fibrosis
Hyperparathyroidism
Familial

125

Chronic Pancreatitis - Pathology

Replacement of pancreas by chronic inflammation and scar tissue
Destruction of exocrine acini and islets

126

Gross Appearance of Chronic Pancreatitis

Fibrotic and necrotic
Inflammation and fibrosis can mimick a tumour in the head of the pancreas

127

Chronic Pancreatitis - Histological Appearance

Exocrine pancreas is replaced by chronic inflammation and fibrosis (first)

128

Carcinoma of Pancreas

Adenocarcinoma
Aetiology Unknown
Weak associated with smoking, diabetes, familial pancreatitis
Poor prognosis (pancreas is intimately related to many important structures. Also, resistant to most forms of chemo)

129

Gross Appearance of Adenocarcinoma of Head of Pancreas

Can invade duodenal wall
Can constrict the common bile duct

130

How can Carcinoma of the Tail of the Pancreas spread?

By direct invasion of the spleen

131

Adenocarcinoma of Pancreas - Histological Appearance

Irregular abortive glands in a dense stroma

132

Adenocarcinoma of Pancreas - Spread

Direct spread to other organs e.g. duodenum, stomach, spleen
Spread to local lymph nodes
Haematogenous spread to the liver