Histopath 1: Systemic Disease

Question 1

Name some infective and non-infective causes of systemic disease

Answer 1

infective:

• HIV
• mycobacterium (TB)

Non-infective:

• Sarcoid
• IgG4-related Disease
• alcohol
• CF
• amyloid

Question 2

What are the main complications of HIV infection?

Answer 2

• Opportunistic infections
• Tumours
• CNS diseases

Question 3

Which are the main opportunistic infections in HIV?

Answer 3

• Pneumocystis jiroveciàPCP pneumonia
• CMV
• Candida
• TB and atypical mycobacteria
• Cryptococcus
• Toxoplasma gondii
• JC papovavirus
• Herpes simplex
• Cryptosporidium, Isospora belli, microsporidia à GIT

Question 4

Which of the HIV opportunistic infections causes PCP pneumonia?

Answer 4

Pneumocystis jirovec

Question 5

Of the HIV opportunistic where does CMV affect?

Answer 5

especially retina and GIT

• I.E. CMV oesophagitis
• Stains brown in immunohistochemistry

Question 6

Which of the HIV opportunistic infections causes meningitis?

Answer 6

Cryptococcus

Question 7

Which of the HIV opportunistic infections causes encephalitis and mass lesions
?

Answer 7

Toxoplasma gondii

Question 8

Which of the HIV opportunistic infections causes progressive multifocal leukoencephalopathy?

Answer 8

JC papovavirus

Question 9

Of the HIV opportunistic where does Cryptosporidium, Isospora belli, microsporidia affect?

Answer 9

GIT

Question 10

Name the main tumours found in HIV and the viruses that cause them

Answer 10

• Kaposi’s sarcoma (HHV-8)
• Lymphoma (systemic [CNS, or body-cavity based], B-cell lymphoma, EBV)
• Other (SSC, anus & cervix, HPV)

Question 11

What is seen in histopathology in Kaposi’s sarcoma?

Answer 11

• Dermis expanded by solid tumour
• Made of spindle-shaped cells–infiltrated by HHV-8
• HHV-8 identified in nuclei of tumour cells

Question 12

What are the main CNS diseases found in HIV?

Answer 12

• Progressive encephalopathy = AIDS dementia complex
• Plus, opportunistic infections and tumours
• CNS lymphoma

Question 13

What are the main histopathological features of Mycobacteria (i.e. TB)?

Answer 13

• Caseating granulomas – in immunocompetent people
  
  • Cavitating TB– predilection to apices of lungs
  • Caseating granuloma = necrotic centres–like cottage cheese
• Demonstration of acid-fast bacilli

Question 14

Which organs can mycobacteria (TB) affect?

Answer 14

• lung
• heart
• lymph nodes
• GIT
• bone
• CNS

Question 15

What are the characteristics of sarcoid? How is it diagnosed?

Answer 15

• NON-caseating granulomas – collection of macrophages with a cuff of lymphocytes around
• Diagnosed as a diagnosis of exclusion

Question 16

Which organs does sarcoid affect?

Answer 16

• Lung
• Liver
• BM
• CNS
• Lymph nodes
• Heart
• Skin
• Salivary glands
• Spleen
• Joints
• Eyes

Question 17

How is Ig4-related disease characterised?

Answer 17

• Inflammation dominated by IgG4-AB producing plasma cells
• Fibrosis and obliteration of veins
  
  • Plasma cell rich inflammatory infiltrate
  • Immunohistochemistry for IgG4

Question 18

What are the IG4-related diseases?

Answer 18

• Salivary and lacrimal glands: Mikulicz syndrome
• Thyroid: Riedel thyroiditis
• Peritoneum: Retroperitoneal fibrosis
• Liver: Biliary obstruction
• Pancreas: Autoimmune pancreatitis
• Mass lesions: Inflammatory pseudotumour

Question 19

Name some conditions caused by alcohol

Answer 19

• Liver: fatty change (steatosis), steatohepatitis, cirrhosis, liver cell cancer (hepatocellular carcinoma)
• GI Tract: acute gastritis, oesophageal varices
• Nervous system: peripheral neuropathy, Wernicke-Korsakoff syndrome etc.
• Cardiovascular system: dilated cardiomyopathy, hypertension, atheroma (and decreases it)
• Pancreas: acute pancreatitis, chronic pancreatitis
• Cancer: oral cavity, pharynx. oesophagus, liver and breast
• Fetal alcohol syndrome

Question 20

Which organs does cystic fibrosis affect and how?

Answer 20

• Pancreas: duct obstruction, exocrine atrophy
• Salivary glands: duct obstruction, atrophy
• Intestine: meconium ileus
• Liver: biliary obstruction, cirrhosis
• Lung: bronchial obstruction, superimposed infection with abscess formation (Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa)
• Male genital tract: infertility, absence of the vas

Question 21

Which organs does cystic fibrosis affect and how?

Answer 21

• Pancreas: duct obstruction, exocrine atrophy
• Salivary glands: duct obstruction, atrophy
• Intestine: meconium ileus
• Liver: biliary obstruction, cirrhosis
• Lung: bronchial obstruction, superimposed infection with abscess formation (Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa)
• Male genital tract: infertility, absence of the vas

Question 22

What is amyloid?

Answer 22

Deposition of an abnormal proteinaceous substance in non-branching fibrils, 7.5-10nm diameter

• Always contains P-component
• Beta-pleated sheet structure
• A variety of proteins can take on this conformation
• Resistant to enzymic degradation

Question 23

What are the classifications of amyloid?

Answer 23

Question 24

What is the staining used in amyloid?

Answer 24

• Stains with Congo Red Dye [TOP]
• Shows apple-green birefringence under polarised light [BOTTOM]

Question 25

What are the clinical effects of amyloid?

Answer 25

Proteinuria, renal failure

Restrictive cardiomyopathy, arrhythmias

Carpal tunnel syndrome

Bleeding on injury

Autonomic neuropathy

Macroglossia

Also deposited in blood vessels, endocrine organs, liver, spleen