pathology

Question 0

urine microscopy:

1. method to do it
2. erythrocytes (normal range, hematuria, dysmorphic, isomorphic/ no cast)
3. leukocytes (normal range, pyuria, persistent sterile pyuria)
4. eosinophils (use what stains, causes)
5. oval fat bodies

Answer 0

1. method
   centrifuge urine specimen for 3-5 min, discard supernatant, resuspend sediment and plate on slide (shake tube vigorously may disrupt cast)
2. erythrocytes
   normal range - 2/3 RBC per high power field
   hematuria = > 2-3 RBC/ HPF
   dysmorphic rbc +/ cast = glomerular bleeding
   isomorphic rbc, no cast = extraglomerular bleeding (eg. bladder ca)

3. leukocytes
normal range up to 3 WBC/HPF
pyuria = > 3WBC/HPF (pus in urine)
indicates inflammation/ infection
persistent sterile pyruia, may be due to chronic urethritis, prostatitis, interstitial nephritis, calculi, papillary necrosis, renal TB, viral infections
pyuria with no cast = acute cystitis

4. eosinophils
   detected using wright or hansel stains (not affected by pH of urine)
   may be due to allergic interstitial nephritis, atheroembolic disease

5.oval fat bodies
= renal tubular cells filled with lipid droplets
seen in heavy proteinuria (eg. nephrotic syndrome)

Question 1

cast in urine

1. what are cast?
2. hyaline cast
3. RBC cast
4. WBC cast
5. pigmented granular cast
6. fatty cast
7. waxy cast

Answer 1

1. cast is cylindrical structure forme dby intratubular precipitation of Tamm-Horsfall mucoprotein, cells may be trapped within matrix of protein
2. hyaline cast - physiological, may be normal, non-specific findings (concentrated urine, fever, excercise)
3. rbc cast - glomerular bleeding (glomerulonephritis, vasculitis)
4. wbc cast - infection (pyelonephritis), inflammation (interstitial nephritis)
5. pigmented granular casts = heme granular cast/ muddy brown, represent acute tubular necrosis/ acute glomerulonephritis
6. fatty cast - heavy proteinuria > 3.5g
7. waxy cast - advanced renal disease/ chronic renal failure

Question 2

nomenclature of glomerular disease, define:

1. focal
2. diffuse
3. proliferative
4. membranous
5. 1st degree glomerular disease
6. 2nd degree glomerular disease

Answer 2

1. focal = < 50% of glomeruli involved
2. diffuse - > 50% of glomeruli involved
3. proliferative = hypercellular glomeruli
4. membranous = thickening of glomerular basement membrane
5. 1st degree glomerular disease = involves only glomeruli, thus 1st degree of kidney
6. 2nd degree glomerular disease = involves glomeruli + other organs = disease of another organ / systemic disease that impacted kidney

Question 3

nephrotic syndrome

• clinical features
• ddx
• complications
• test
• general measures

Answer 3

clinical features
- ask about acute/ chronic infections, drugs, allergies, systemic symptoms
(vasculitis: inflammatory disorder of blood vessel walls; features of systemic - fever, malaise, weight loss, arthralgia, myalgia, skin - purpura, ulcers, livedo reticularis, nail bed infarct, digital gangrene, eye - episcleritis, scleritis, visual loss, ENT epistaxis, nasal crusting, stridor, deafness, pulmonary -haemoptysis, dysnpnoea due to pulmonary hemorrhage, cardiac - angina/ MI, heart failure, pericaridits, GI - pain, perforation, malabsoprtion, renal - HTN, haematuria, proteinuira, cast, renal failure, glomerulonephrtis, neurology - stroke, fits, chorea, psychosis, confusion, impair cognition, altered mood, testicular pain)
symptoms of malignancy

signs - oedema (typically pitting, dependent= increase with gravity), often at periorbitally (tissure resistance is low), peripherally in limbs - genital oedema, ascites, anasarca (fluid in organs and cavities with severe oedema and tissue harden; late sign; can also occur in CCF, liver failure, protein losing enteropathy, fetal hydrops, capillary leak syndrome with monoclonal gammopathy)
bp increase / normal

ddx: CCF (increase JVP, pulmonary oedema, mild proteinuria), liver disease (decrease albumin)

complications:
increase susceptibility to infection eg. cellulitis, streptococcus infections, spontaneous bacterial peritonitis in 20% of adult patient because decrease serum IgG, complement activity and T cell function (due to loss of immunoglobulin in urine and immunosupressive tx)

thromboembolism - up to 40% eg. DVT/PE, renal vein thrombosis due to hypercoagulable state is partly due to increase clotting factor and platelet abnormalities

hyperlipidaemia - increase cholesterol and triglycerides due to hepatic lipoprotein synthesis in response to low oncotic pressure

test:
blood - FBC, U&E, LFT, ESR, CRP, immunoglobulins, electrophoresis, complement (C3, C4), autoantibodies: ANA, ANCA, anti-dsDNA, anti-GBM, blood culture, ASOT, HBsAg, anti-HCV
urine - RBC casts, MC&S, bence-jones protein
24 hour urine - please discard first urine sample, for protein/ spot urine test (prefer morning) for protein: Cr ratio/ albumin: Cr ratio (less error, quicker result, as accurate as 24 hr)
CXR, renal US +/- renal biopsy
check cholesterol
renal biopsy - DO IN ALL ADULTS (children most have minimal change GN, so steroids tried initially - biopsy if proteinuira does not reduce after 1 month / features of other cause eg. 1g/24hr then aim bp 125/75 - ACEi, ATA (address issue of smoking, exercise, diet)