histo path Flashcards
Neutrophils
Acute inflammation (sterile or non-sterile)
Raised due to corticosteroid use
Macrophages
Late acute inflammation
Chronic inflammation (including granulomas e.g. Sarcoidosis)
Lymphocytes
Chronic inflammation
Lymphoma (sheets of clonal cells ie. Identical)
Plasma Cells
Chronic inflammation
Myeloma
Eosinophils
Allergic reactions
Parasitic infections
Tumours e.g. Hodgkin’s disease
Mast Cells
Allergic reactions
Parasitic infections
Fontana stain :
+ve for melanin
identifying Capsule-Deficient Cryptococcus Neoformans and typical Cryptococcus Neoformans.
Congo Red stain :
+ve for Amyloid (Apple green birefringence)
Prussian Blue:
+ve for iron (haemochromatosis)
Go-to stain for most histological samples is?
Hemotoxylin and Eosin (H&E).
what happens to serum transferrin in iron def anaemia and why ?
Serum Transferrin increases in IDA, as the liver increases transferrin production to
bind to as much available iron it can to compensate for low iron levels
Evolution of MI – Histological findings**:
Under 6 hours - normal by histology (CK-MB also normal)
6–24 hrs - loss of nuclei, homogenous cytoplasm, necrotic cell death
1-4 days - infiltration of polymorphs then macrophages (clear up debris)
5-10 days - removal of debris
1-2 weeks - granulation tissue, new blood vessels, myofibroblasts, collagen synthesis
Weeks-months - strengthening, decellularising scar tissue.
most common cause of RV failure
Most common cause is secondary to LVF but can be primarily caused by chronic severe pulmonary hypertension
most common cause of LVF is CAD
what is dilated cardiomyopathy and is its mechanism of heart failure ?
dilated = too thin
systolic dysfunction
restrictive cardiomyopathy what is it ?
too stiff
diastolic dysfunction
Hypertrophic obstructive cardiomyopathy (HOCM) - what is it ?
– septal hypertrophy resulting in an outflow tract obstruction
pathogensis of rheumatic fever ?
you get a strep throat infection usually 2-4 weeks before
cell-mediated immunity and antibodies to streptococcal antigen cross-react with myocardial antigens
main pathogen of infection preceeding rheumatic fever ?
Lancefield group A strep is the main pathogen.
what is criteria for rheumatic fever ?
Jones criteria
eviednce group A strep infection + 2 major criteria or 1 major + 2 minor criteria
Major criteria:
Carditis
Arthritis
Sydenham’s chorea
Erythema marginatum
Subcutaneous nodules
Minor criteria:
Fever
Raised CRP/ESR
Migratory arthralgia
Prolonged PR
Prev. rheumatic fever
Malaise
Tachycardia
Evidence of GAS infection:
Positive throat culture
Elevate AsO
Recent scarlet fever
rheumatic fever important histology to know
Histology: Beady fibrous vegetations (verrucae), Aschoff bodies (small giant-cell granulomas) and Anitschkov myocytes (regenerating myocytes).
treatment for rheumatic fever ?
NSAIDs (e.g. ibuprofen) are helpful for treating joint pain
Aspirin and steroids are used to treat carditis
Prophylactic antibiotics (oral or intramuscular penicillin) are used to prevent further streptococcal infections and recurrence of the rheumatic fever. These are continued into adulthood.
Monitoring and management of complications
in infective endocarditis, the Bacteraemia secondary to:
- Poor dental hygiene (Strep. Viridans)
- IVDU
- Soft tissue infection
- Dental treatments
- Cannulas/lines
- Cardiac and valvular surgery/pacemakers
- Previously damaged valve e.g. post-rheumatic fever
difference between acute and subacute infective endocarditis ?
Acute:
- staph aureus / strep pyogenes
high virulence
vegetation is larger and more localised
spread is to the aorta
Subacute:
Strep. viridans, Staph. epidermis, HACEK* (culture -ve), Coxiella, Mycoplasma,candida
Low
Friable, soft thrombi. A few mm in size.
Chordae
what valve in infective endocarditis ?
Usually mitral/aortic valve unless IVDU when right-sided valves involved.