Pathology deck Flashcards
Define amyloidosis
Improper collection of Beta pleated sheets of amyloid protein in the extracellular matrix. It is a life-threatening condition as humans lack the enzyme to break down this protein structure
How do you classify amyloidosis
Al - congenital and primary
This is caused by clonal proliferation of plasma cells producing this amyloid immunoglobulin
AA - secondary to chronic inflammation (in RA, IBD, TB, bronchiectasis, renal cell carcinoma)
Inflammation forces macrophages to secrete interleukin that then stimulates hepatocytes to produce amyloid protein A.
ATTR - autosomal dominant and most commonly affected protein is tranthyretin
What are the clinical features of AL amyloidosis
Kidneys: Proteinuria and nephrotic syndrome
Cardiac: Restrictive cardiac disease and arrythmias
Nervous system: Peripheral and central symptoms
GI: Malabsorbtion, bleeding, obstruction and perforation
Vascular: purpura
Clinical features of AA amyloid
Hepato and splenomegaly and proteinuria
How is amyloid diagnosed
Tissue biopsy
Subcut fat or rectal tissue is regarded as the best sample
Isotope scanning can also show hot spots of amyloid deposits
How is amyloidosis managed
AA can be controlled if underlying inflammation is controlled
AL needs chemo and eradicating abnormal plasma cells
Stem cellls
Supportive tx
It has poor survivial and the median survivial rate is 1-2 years
Which thyroid cancer causes amyloid deposition?
Meduallry as amyloid is composed of calcitonin
Where can isolated amyloid deposits be found
Larynx
Anwhere in the urinary tract
Aorta
Pituitary
Amyloid microsopy
Congo red stain shows apple gree birefingence under polarized light
What is the pathogenesis of calcification of the aortic valve in aortic stenosis
Lipid accumulation, inflammation and clacification
What are the symptoms of aortic stenosis
Syncope, angina and dyspnoea. The symptoms may not present until they are life-threatening and hence patients can also present with sudden cardiac death
How would you investigate for aortic stenosis
ECG, ECHO, CT angio, cardiac CT/MRI and exercise tolerance test
Aortic sclerosis vs aortic stenosis
Sclerosis is calcification of the valve without a significant gradient across the valve, this may progress into aortic stenosis
Do patients that undergo routine aortic valve replacement need prophylactic abx
No, I would consult the nice guidelines but the only exception to this would be if a patient was having a contaminated surgery, then abx to cover for those bacteria would be considered
What are organisms that commonly cause IE
HACEK organisms Strep Viridans and groups B and D, staph auerus (most common), Candida, enterococci, Pseudomonas aueriginosa
What is the definition of AKI
Abrupt reduction in GF resulting in the reduction in the ability of the kidneys to excrete nitrogenous waste. This is reflected by a rise in serum creatinine and urea
Biochemical cutoff is an increase in serum creatinine of 1.5-2x
Over what timescale does AKI normally develop
48 hours
What is a normal U and Cr
U 2.5-7.8 mmol/L
Cr 60-110 mcrmmol/L for men and 45-90mcrmmol/L for females
Emergency management of pulmonary oedema
ABCDE approach
Stop IV fluids
Sit the patient up
Oxygen
furosemide
Consider HF
CXR
What is normal urine output
0.5ml/kg/hr for adults and 1 for child
Define oliguria
<0.5ml/kg over a 6 hour period or <400mls over a 24 hour period
What is the most common cause of anuria in a surgical patient
Blocked catheter
In which decade is appendicitis most common
Second decade of life 10-20, slightly more common in males 1.4:1
In what positions can appendix be found
Retrocaecal 75%
Pre and post ileal 5%
Pelvic 20%
What are the boundaries of the foregut, midgut and hindgut
Foregut: mouth to 2nd part of du
Midgut: 2nd part of duo to 2/3rd the way of transverse colon
Hindgut: End of midugut to rectum
What is the obturator sign
Pain on flexion and internal rotation of the hip joint, this irritates the obturator internus
Through which general visceral nerve does the pain of appendicitis travel
Lesser splanchnic nerve, T10 and T11 is the root value
Scoring systems used for appendicitis
Alvarado and Appendicitis inflammatory response score
What are the types of acites
Transudative and exudative:
Transudate is protein <25g/mL
Exudate is >25g/mL protein
SAAG
Serum albumin and ascites albumin gradient
<11 exudative low gradient §
>11 is transudative highgradient
Give some examples of transudates
Portal hypertension caused by liver cirrhosis, portal vein thrombosis, budd chiari syndrome
Low albumin production: Liver impairment, starvation and nephrotic syndrome
Give some examples of exudates
Caused by inflammation and infection resulting in protein loss
4Ps
Peritonitis
post-irradiation
peritoneal mets
pancreatitis
How does acites form, with respect to the starling equation
The starling equation represents the movement of fluid across blood vessels and the interstitium with respect to hydrostatic and oncotic pressure
Blood moves from arteries to cap and then to veins
In the artery, hydrostatic pressure is higher than oncotic pressure and hence net movement of fluid is into the interstitium
In the vein, hydrostatic pressure is lower than the oncotic pressure and hence fluid is pulled back in, rest of the fluid is carried by the lymph
What is Rh
Symmetrical autoimmune inflammation of the joints with systemic manifestations. Commonly more females are affected than males. RH+ve in 70% of cases
5th or 6th decade is the most common decade of presentation
What is the pathology of RH
Joint effusions and inflammation, increase in the number of T cells and macrophages. Formation of granulation tissue and
What are some extra-articular manifestations of Rh
Nodules
Lymphadenopathy
Vasculitis
What are rheumatoid nodules
Most commonly seen on extensor surfaces
Seen in 20% of patients with RA
Accumulation of collagen with a central area of necrosis and surrounding cells including fibroblasts and macrophages
What happens on a radiograph of a joint with Rh
Loss of joint space and erosions, joint swelling, juxta-articular osteopenia
Define atherosclerosis
It is the thickening of vasculature as a result of buildup of fatty tissue on the inside of the vessels
What is the pathogenesis of atherosclerosis
It begins due to endothelial dysfunction. Then there is macrophages that form foam cells with a lipid-rich core.
Secondly, there is migration of smooth muscle cells to form a fibrous cap
This process ultimately leads to stenosis and can lead to obstruction of the lumen of the vessel. This leads to thrombosis or possible infarction of the tissue supplied by the vessel
How do tamsulosin and finasteride work
Finasteride: 5 alpha-reductase inhibitor and prevents the conversion of testosterone to dihydrotestosterone and hence reduces the size of the gland
Tamsulosin: Alpha 1 adrenergic receptor antagonist and relaxes smooth muscles to make urinary flow better
What is a fibroadenoma
Proliferation and collection of epithelium and stromal tissue of the duct lobes
Well rounded, oval shaped and mobile
Most common site is the upper and outer quadrant of the breast
Can be multiple and bilateral
How do you score the breast triple assessment
1-5 5 being malignant and 1 besing normal
What are breast cysts
They are distended, fluid-filled involuted lobules that develop in peri-menopausal females
They can be single or multiple and often present as smooth discrete lumps that are painful
Mammography and USS to confirm diagnosis, if aspirations are blood stained then patient needs triple assessment
What causes true mastalgia
Caused by an exaggerated response of breast tissue to hormones in menstruation
First line is OTC meds and soft fitting bra while sleeping
a secondary referral is then required and a medication called danazol that is an anti-gonadotrophin agent can be used
What is Mondor disease
Thrombophlebitis of the superficial veins of the breast and chest wall. Treatment os conservative with OTC pain meds and it can take months to heal
When is gestational nipple discharge the most common
2nd trimester
What is the commonest malignancy of the biliary tree
Cholangiocarcinoma: It is an adenocarcinoma of the epithelial lining of the bile duct
Commonest cause in the west is PSC followed by Hep C, HIV and congenital liver disease
In developing worlds it is most commonly caused by liver flukes
What is a klatskin tumour
A specific tumour originating at the junction of the left and right hepatic ducts
Any specific tumour markers for cholangiocarcinoma
CEA, CA19=9
Most tumours present when they are unresectable and hence patients are offered best supportive care.
Disease recurrence rates are also very high
What are the most common types of bladder cancer
Transitional and squamous cell carcinoma
Squamous cell carcinoma is more common in Africa due to present of Schisto H
In developing countries, 70% are SCC
Others include adenocarcinoma, small cell, sarcoma and secondary met
What are the surgical management options for bladder cancer
TRansurethral resection of bladder tumour, this is the most common
partial cystectomy: rarely offered
radical cystectomy: Involved removal of the bladder and the urethra and lymph nodes. In men, prostate, seminal vesicles and vas deferens are also removed
Intravesical mitomycin C chemo or BCG immunotherapy
Disinfection vs sterilization
Disinfection removes a number of viable organisms but not all. Sterilisation removes all including spores
Changes for hypokalaemia
What is the scoring system for NEC FASC
LRINEC
Types of nec fasc
What is clostridium
Gram positive, rod shaped, spore forming, anaerobic commonly found in soil, clothing and faeces
Perfringins, tetani, botulinum, difficile
In mild to moderate disease can give oral metro or vanc
In severe: oral vanc or oral fidoxamicin
IV immunotherapy or faecal transplant may be required in very severe cases
How are FAP and HNPCC inherited
Both are autosomal dominant
FAP: APC on Ch5
HNPCC: mutations on CH 2 and 3
APC gene mutation that then causes a mutation in KRAS and DCC and finally p53 tumour suppressor gene
Where does colorectal cancer predominantly metastasize to
Brain, bone, lung and liver
What types of liver tumours are there
Benign: Hemangioma, adenoma
Malignant: HCC, Cholangiocarcinoma, angiosarcoma, hepatoblastoma
Secondary: Metastasis (This is the most common type)
What is H.pylori
Gram-negative bacterium found in the stomach
It uses flagella to move away from acidic contents in the stomach and survive
It produces the enzyme urease that converts urea to CO2 and Ammonia. The ammonia then binds to the H+ to neutralise the gastric acid
it releases certain protease and along with the ammonia, erode the gastric contents
What is the lifetime risk of developing a peptic ulcer with H pylori
10-20 %
1-2% of the time H pylori is associated with gastric mucosa
How can H Pylori be diagnosed
Carbon 13 breath test or stool antigen
CLO test on a gastric mucosa sample but this depends on the urease production
What is the H Pylori eradication therapy
Twice daily for 7 days of PPI + amox + Metro/clarithromycin
If pen allergic then PPI + Clar + met
FACT
Thymus also develops from the 3rd pharyngeal arch and hence it may drag the inferior parathyroids down with it
What does normal parathyroid tissue contain
Chief cells and oxyphil cells
What are the gell and coombs hypersensitivity reactions
What are the contributors to an infection
Infectious agent, susceptible host and a poorly perfused area
Name to fungi that cause abscesses and sinuses
Histoplasma and candida
What are the common factors that create a good environment for infection
hypoxia, hypercapnia, poor perfusion, acidosis
What is the qSOFA score
Altered mental state/ GCS
RR >22
SBP <100
What is Rheumatic fever
Disease affecting the heart, joints, skin and bones. It can develop 2-4 weeks after an unrelated pharyngeal infection A beta-haemolytic streptococci.
It is a type 2 hypersensitivity reaction
It is uncommon in the west but still common in developing countries
What are the properties that you look for in a drape
Breathable, non-inflammable, can handle cold, hot and wet stresses
accept or dissipate electrical current
Non-toxic
What are the risk factors of developing thyroid cancer
being female
radiation
FHx
Obesity
history of goitre
20-25 % of medullary is familial and papillary and follicular is more sporadic with only 5-10% being familial
What are the causes of hypoparathyroidism
Thyroid surgery
Autoimmune
Post irradiation
What is a nevus
A benign proliferation of normal constituent cells of the skin
Spitz nevus, shagreen patch, port wine stain, Strawberry neveus
Is melanoma more common in males or females
50-50
How can you tell a melanoma
Irregular shape and multicoloured
growing rapidly
Change in size or sensation
What is more common UC or Chrons
UC
What are the extraintestinal manifestations of UC and chrons
Aphthous ulcers
Pyoderma gangrenosum
Iritis
Erythema nodosum
Sclerosing cholangitis
Arthritis
Clubbing of fingertips
A PIE SAC
What are the different kinds of necrosis
What is the difference between apoptosis and necrosis
What are 2 pathological examples of hyperplasia
BPH and adrenal glands in cushings syndrome
What are 2 physiological and 2 pathological causes of hypertrpphy
Physio: Uterus in preg and skeletal muscles on exercise
Path: Thyroid in graves disease and cardiomopathy
What is a hamartoma
Tumour like malformation due to disorganised arrangement of different amounts of normal cells
Eg: Peutz Jeghers polyps, hemangiomas
What is the difference between carcinoma and sarcoma and their spread
Carcinoma is abnormal growth of epithelial tissue and sarcoma is connective tissue
Carcinoma spread through lymph and sarcoma spread through blood
What cancers typically spread to the bone
Breast, Prostate, renal, thyroid, bronchus
What are the stages of acute inflammation
Vasoconstriction initially and then vasodilation
Increased vascular permeability
Migration of white blood cells
Phagocytosis
resolution or progression to chronic inflammation
What is the complement cascade
It is a part of the innate immune response that aids in development of membrane attack complexes.
Classic activation involved antigen and antibody binding
Alternative pathway is when c3 comes in direct contact with micro-organisms
Lectin pathway
What is a granuloma
Collection of epitheloid macrophages
Granulomatous inflammation is type of chronic inflammation that is caused by the presence of above mentioned cells as they form giant cells
Caseating: TB
Non caseating: sarcoid, chrons
Define a clot
A collection of solid material formed by the constituents of bloods
What is an embolus
A collection of undissolved material that partially breaks off and is carried from one place to another
What leads to the development of thrombus
Virchows triad: Abnormal blood flow, hypercoagulable state and endothelial injury
What are the benefits of cytology
Cheap and easy with quick result
Minimally invasive procedure to get sample
How do you diagnose IE
2 major criteria or 1 major and 3 minor on the Dukes criteria
Major
2 separate + blood cultures with IE organisms
Evidence of endocardial involvement
How do you diagnose rheumatic fever
2 major criteria or 1 major and 2 minor according to the Modified Jones criteria
Major (CEPS)
Carditis
Erythema marginatum
Polyarthritis
Sydenhams chorea
Why is IE so hard to treat
The valves of the heart do not recieve specifi blood supply and hence this makes it harder for immune cells and antibiotics to get through
What are the possible benefits of the use of tumour markers
Screening
Diagnostic
Measuring response to treatment
Monitoring for reccurence
What is the difference between staging and grading
Staging is describing the extent of the tumour based on size, spread.
Grading is describing differentiation of the tumour based on histology
Can you name some staging methods
Dukes
Clarkes
Breslow
TNM
What is the Dukes staging
For Colorectal cancer
A - confined to bowel wall (95-100 survival)
B - through bowel wall (65-75)
C- lymph nodes (30-40)
D - Distant mets (5-10)
What is a grading system that you know if
Gleason score for prostate cancer
2-10
What is the differnece between submandibular calculi and parotid calculi
Parotid tend to be multiple and small and within the gland
Submandibular tend to be large and single and intraductal
What % of salivary glands are radio-opaque
80-90% of the submandibular stones and 60% of parotid
Parotid gland tumours
85% benign - pleomorphic adenoma and Warthins tumour
15% malignant: Mucoepidermoid carcinoma and adenoid cystic carcinoma