Histopathology 13 - Histopathology of Systemic Disease Flashcards
What can JCV infection in HIV positive patients lead to?
Progressive multifocal leukoencephalopathy
What is the most common opportunistic infection in HIV positive patients?
CMV
Which herpes virus causes kaposi sarcoma?
HHV8
What is the main histological finding in sarcoidosis?
Non-caseating granulomas
How does end-stage sarcoidosis appear on CXR?
‘Honeycomb’ lung
What is a granuloma made up of?
Lymphoid cells and giant cells
What colour does IgG4 stain when positive?
Brown
Recall 3 diseases caused by IgG4 inflammation
Riedel thyroiditis
Autoimmune pancreatitis
Inflammatory pseudotumours
What is the structure of amyloid?
Beta pleated sheet that forms non-branching fibrils
What is the cause of AA amyloidosis?
Chronic inflammation
Which conditions are particularly implicated in the development of AA amyloidosis?
Crohn’s
Rheumatoid arthritis
What conditions can cause AL amyloidosis?
Myeloma
B cell neoplasms
What is the link between transthyretin and amyloidosis?
Transthyretin mutation can –> cardiac amyloid
What stain can be used for amyloid?
Congo red - gives green birefringence under polarised light
What opportunistic infections are associated w/ HIV?
PCP CMV Candida TB Cryptococcus Toxoplasma gondii JC virus Herpes Cryptosporidium
What tumours are associated w/ HIV?
Kaposi Sarcoma
Lymphoma (EBV, B cell)
What CNS disease is associated w/ HIV?
Progressive multifocal leukencephalopathy
What is the main feature of TB infection? what staining?
Caseating granulomas -
Ziehl-Neelsen stain reveals acid fast bacilli
What is the main feature of sarcoidosis? - other features + diagnosis?
Non-caseating granulomas
Also causes:
- Erythema nodosum
- Increased levels of ACE and Ca in blood
- LATE STAGE = honeycomb lung
This is a diagnosis of exclusion
What is IgG4 Related Disease caused by?
IgG4 antibody producing plasma cells
What is amyloidosis? Where do they come from + which conditons
Deposition of abnormally folded proteins (can basically deposit anywhere causing a whole host of symptoms)
AA Amyloid (from serum amyloid A) - caused by chronic inflammatory states (eg. RA, UC, Crohns etc)
AL Amyloid (from light chains) - caused by multiple myeloma
Staining for amyloidosis?
Congo Red dye causing apple green birefringence
How can you differentiate between TB and sarcoid granulomas?
TB = caseating
Sarcoid = non-caseating
What is the difference between the pathology of AA and AL amyloidosis?
AA = formed as a result of a chronic inflammatory state
AL = formed from light chains in multiple myeloma
