Pathology Flashcards
Ghon complex -
Ghon complex - primary TB and regional nodal involvement
o Macrophage internalisation
o Granulomata – epitheloid histocytes
o T4 hypersensitivity
Cancer most common in non-smokers
Peripheral Adenocarcinoma – most common in non-smokers
Organisms for Malignant otitis externa
Malignant otitis - Pseudomonas aeruginosa - Severe pain, headaches and granulation tissue
Diabetes (90%) or immunosuppression (illness or treatment related)
Severe, unrelenting, deep-seated otalgia
Temporal headaches
Purulent otorrhea
Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
Malignant hypertension results in
Malignant hypertension - Fibrinoid necrosis
Reed Sternberg cells
Hodgkins lymphoma - Reed Sternberg cells
Most favourable prognosis for Hodgkins lymphoma
Classical lymphocyte predominant
Asteroid Bodies
Asteroid Bodies - Sarcoid
% of sarcomas are found in the extremities.
40% of sarcomas are found in the extremities.
Most common anal cancer and cause
Anal SCC (most common) – HPPV 16 (Less 18)
Granulomas are…
Granulomas are organised collections of macrophages, different to giant cells
nose bleed, hearing loss, face/ear pain, soft palate paralysis
nasoparyngeal carcinoma – nose bleed, hearing loss, face/ear pain, soft palate paralysis
- EBV risk factor
Concentric ring of epithelial cells seen in the medulla of the thymus (pharyngeal pouch 3+4)
Hassall’s corpuscles
Watercress farmer - jaundice - organism?
Watercress farmer – fasciola hepatica –
Jaundice and bile duct hyperechoic dilation.
Aka liver fluke, nematode.
Stool or serology, triclabendazole
cartilage, ciliated epithelium
Hamartoma: CT,
to kill tubercle bacilli
Autoclave to kill tubercle bacilli
laxative abuse
Melanosis coli
GVDH
Lymphocyte proliferation not neutrophil
Gigantic leg
Mosquito bite in congo, Indian BL
Filriasis- gigantic leg Wuchereria bancrofti - nematode– treat with diethylcarbamazepine
Ascending UTI
Ascending UTI – E Coli
Fournier’s Gangrene
E-coli and bacteroides
To sterilise endoscopic equipment
Glutaraldehyde
Fistulae, sulphur granules, poor healing
Fistulae, sulphur granules, poor healing
Actinomycosis – Gram +ve anaerobes, long term penicillin
Colon carcinoma + endocarditis
Streptoccus Bovis - gram +ve
Work with sheeps and dogs – LFTs + Eosinophilia
Echinococcus granulosus
Hydatid cyst – calcified – work with sheeps and dogs – LFTs + Eosinophilia (liver, intestines)
Meditarrean, Middle Eastern, Biliary cysts + Urticarial rash
Hydatid cysts – Echinococcus Granulosus –
T1 Hypersitivity – cysts are allergens
Most common food borne illness
(resistant to cooking)
Onset is hours after eating
C. Perfringens
Foodborne illness - within minutes of eating
Minutes with staph aureus (preformed enterotoxin)
Associated with gas grene
C. Perfringens
Waterhouse - Friderichsen syndrome - adrenal gland bleeding and failure due to severe infection - mostly commonly due to.
most commonly Meningococcus - Neisseria meningitidis.
Waterhouse - Friderichsen syndrome - adrenal gland bleeding and failure due to severe infection -
Osteomyelitis in Sickle
Osteomyelitis in Sickle: E.Coli>Staph Aureus
Achalasia - Infective destruction of myenteric plexus ganglia, heart, CNS, spleen.
Achalasia – trypanosoma Cruzi destruction of myenteric plexus ganglia, heart, CNS, spleen. Only acute infection curable
SEVERE Abdo pain with diarrhoea – more likely to be
SEVERE Abdo pain with diarrhoea – more likely campylobacter jejuni
Diarrhoea in immune suppressed – renal transplant
cryptospirodium - cysts
Relative bradycardia in
Relative bradycardia in typhoid fever
CMV infection most common in
CMV infection most common in solid organ transplants
Birds touching your milk?!
Birds touching your milk?! Compylobacter jejuni!
Egypt, swimming pool, diarrhoea
Giardia – resistant to chlorination.
First line treatment is with metronidazole
Group A Strep add what to flucloxacillin
Group A Strep – add penicillin to flucloxacillin
Coughing, abdo discomfort, no prurois anii, Indian/Far East
orms and eggs on microscopy – Ascaris Lumbricoides
Treatment is with mebendazole
Management of hepatitis B
Pegylated interferon-alpha
lamivudine, tenofovir and entecavir
Complications of hepatitis B infection
Chronic hepatitis (5-10%) Fulminant liver failure (1%) Hepatocellular carcinoma Glomerulonephritis Polyarteritis nodosa Cryoglobulinaemia
Management of chronic Hep C
a combination of pegylated interferon-alpha and ribavirin are used, up to 55% of patients successfully clear the virus
Hep C management complications
ribavirin - side-effects: haemolytic anaemia, cough. Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
interferon alpha - side-effects: flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
HIV Antigen test
p24 antigen test
usually positive from about 1 week to 3 - 4 weeks after infection with HIV
sometimes used as an additional screening test in blood banks
The commonest organism in isolated pathogen infection in Necrotising fasciitis
Streptococcus
A similar principle but the infection is more superficially sited than necrotising fasciitis and often confined to the trunk
Meleneys gangrene
Who should be screened for MRSA?
all patients awaiting elective admissions (exceptions include day patients having terminations of pregnancy and ophthalmic surgery. Patients admitted to mental health trusts are also excluded)
in the UK all emergency admissions are currently screened
How should a patient be screened for MRSA?
nasal swab and skin lesions or wounds
the swab should be wiped around the inside rim of a patient’s nose for 5 seconds
the microbiology form must be labelled ‘MRSA screen’
Suppression of MRSA from a carrier once identified
nose: mupirocin 2% in white soft paraffin, tds for 5 days
skin: chlorhexidine gluconate, od for 5 days. Apply all over but particularly to the axilla, groin and perineum
The following antibiotics are commonly used in the treatment of MRSA infections:
vancomycin
teicoplanin
Some strains may be sensitive to the antibiotics listed below but they should not generally be used alone because resistance may develop: rifampicin macrolides tetracyclines aminoglycosides clindamycin
Osteomyelitis
S aureus and occasionally Enterobacter or Streptococcus species
Septic arthritis…
Most common organism overall -
young adults who are sexually active -
Most common organism overall is Staphylococcus aureus
In young adults who are sexually active Neisseria gonorrhoeae should also be considered
The BNF currently recommends flucloxacillin or clindamycin if penicillin allergic
Alpha haemolytic streptococci
Streptococcus pneumoniae (pneumococcus) - pneumonia, meningitis and otitis media Streptococcus viridans
Beta haemolytic streptococci
These can be subdivided into group A and B
Group A
most important organism is Streptococcus pyogenes
responsible for erysipelas, impetigo, cellulitis, type 2 necrotizing fasciitis and pharyngitis/tonsillitis
immunological reactions can cause rheumatic fever or post-streptococcal glomerulonephritis
erythrogenic toxins cause scarlet fever
Group B
Streptococcus agalactiae may lead to neonatal meningitis and septicaemia
Staphylococcus aureus
Facultative anaerobe Gram positive coccus Exo toxin -toxic shock syndrome Enterotoxin - gastroenteritis Resistance to methicillin (and other antibiotics) is mediated by the mec operon
Streptococcus pyogenes
Gram positive, forms chain like colonies, Lancefield Group A Streptococcus
beta haemolysis on blood agar plates
superantigens such as pyogenic exotoxin A which results in scarlet fever
Escherichia coli
Gram negative rod
Facultative anaerobe, non sporing
Enterotoxigenic E-Coli produces an enterotoxin (ST enterotoxin) that results in large volume fluid secretion into the gut lumen (Via cAMP activation)
Enteropathogenic E-Coli binds to intestinal cells and cause structural damage
Campylobacter jejuni
Curved, gram negative, non sporulating bacteria
commonest causes of diarrhoea worldwide
Remains a differential for right iliac fossa pain with diarrhoea
Self limiting infection so antibiotics are not usually advised. However, the quinolones are often rapidly effective.
Helicobacter pylori
Gram negative, helix shaped rod, microaerophillic
Those carrying the cag A gene may cause ulcers
colonises the gastric antrum and irritates resulting in increased gastrin release and higher levels of gastric acid
These patients will develop duodenal ulcers.
In patients who are colonised 10-20% risk of peptic ulcer, 1-2% risk gastric cancer, <1% risk MALT lymphoma.
