Renal pathology Flashcards
Types of renal carcinoma
Clear cell - well differentiated
Papillary (15%) - dialysis-associated cystic disease, >5mm;
Chromophobe - pale eosinophilic cells.
Also Wilms’ - children, small round blue cells, RUQ mass.
RF for renal carcinoma
Smoking, obesity, hypertension, unopposed oestrogen, heavy metals, CKD.
Features of renal carcinoma
Haematuria, palpable mass, costovertebral pain.
Paraneoplastic syndrome: polycythaemia, ^Ca, HTN, Cushing’s, amyloid.
Classification of (non-neoplastic) renal pathogy
- Glomerulus:
- Nephritic
- Nephrotic- Tubules and interstitium
- Acute tubular necrosis (acute tubular injury)
- Pyelonephritis
- Interstitial nephritis
- Blood vessels
- HUS
- TTP
- Tubules and interstitium
Nephrotic syndrome features
Proteinuria (3g/24h), hypoalbuminaemia, oedema.
“Swelling” (facial in children), “frothy urine”.
Due to loss of foot processes (only seen on EM).
Primary causes of nephrotic syndrome
- Minimal Change Disease
- Membranous glomerular disease
- Focal segmental glomerulosclerosis
All show loss of foot processes on EM.
Minimal change disease
Chidren.
No change on microscopy, no immune deposits, (loss of foot processes on EM).
90% respond to steroids. 5% get ESRF.
Membranous glomerular disease
Adults.
Diffuse thickening of basement membrane.
EM: lose foot processes, subepithelial deposits.
Immunofluorescence: Ig and complement all along BM.
Poor response to steroids. 40% get ESRF eventually.
Can be 2o to SLE, infection, drugs, cancer.
Focal segmental glomulerosclerosis
Adults, AC.
Bits of glomerular scarring, with hyalinosis.
Immunofluorescence shows Ig and complement in scarred areas.
50% respond to steroids, but 50% get ESRF.
Can be 2o to obesity or HIV nephropathy.
Seondary causes of nephrotic syndrome
- Diabetes (Kimmelstiel Wilson nodules);
2. Amyloidosis (chronic inflam, Ig light chains, macroglossia, heart failure, big liver).
Nephritic syndrome features
Haematuria,
dysmorphic RBCs and red cell casts in urine.
?: hyertension, oliguria, proteinuria, ^urea and Cr.
Causes of nephritic syndrome (5)
- Acute post-infectious GN (after strep)
- Rapidly progressive / crescentic GN
- IgA nephropathy (Berger disease)
- Hereditary nephritis (Alport syndrome)
- Thin basement membrane disease (benign familial haematuria)
Acute post-infectious glomerulonephritis
1-3 weeks after strep throat or impetigo (Staph aureus or Strep pyogenes (group A beta haemolytic));
Immune complexes damage BM;
Raised ASO titre, low C3;
Biopsy:
LM: ^ cellularity,
FM: granular deposits of Ig and C3 in GBM,
EM: subendothelial humps.
Rapidly progressive / crescentic glomerulonephritis
Most aggressive: ESRF in weeks. Pronounced oliguria and renal failure.
All show crescents on LM. Classified by immunological findings.
Type 1 Rapidly progressive (crescentic) GN
Anti-GBM Ab, because Goodpasture Ab to COL4-A3. HLA-DRB1. LM: Obviously crescents. FM: Linear IgG deposits in GBM. Also lungs (pulmonary haemorrhage).
Type 2 Rapidly progressive (crescentic) GN
Immune complexes.
Due to SLE / IgA nephropathy / Acute post-infectious GN.
LM: Obviously crescents.
FM: Granular (lumpy bumpy) IgG immune complexes.
Type 3 Rapidly progressive (crescentic) GN
Pauci-immune / ANCA associated,
ie. no anti-GBM or immune complexes.
Due to c-ANCA (Wegener’s) or p-ANCA (microscopic polyangiitis).
Vasculitis elsewhere - rashes and pulmonary haemorrhage.
IgA nephropathy
= Berger disease.
Frank haematuria 1-2 days after upper RTI. Recurrent.
Commonest GN worldwide.
IgA immune complexes deposited in glomeruli.
Hereditary nephritis
= Alport’s syndrome
X-linked mutn in type IV collagen alpha 5 chain.
Nephritic syndrome + sensorineural deafness + eye problems (lens & cataracts).
5-20yo. Progresses to ESRF.
Thin basement membrane disease
= benign familial haematuria
ie. usually doesn’t cause nephritic syndrome, renal function usually normal.
AD, type IV collagen alpha 4 chain.
Prevalence 5%.
Causes of asymptomatic haematuria
Thin basement membrane disease,
IgA nephropathy (Berger),
Alport’s.
Acute pyelonephritis
Bacterial infection of kidney, usually ascending E. coli.
Fever, flank pain, leukocytes, ?urinary Sx.
Leukocytic casts in urine.
Ciprofloxacin or co-amox.
Chronic pyelonephritis
Chronic bacteria, inflam, scarring.
Due to
- obstruction: calculi, posterior urethral valves
- vesico-ureteric reflux = reflux nephropathy
Acute interstitial nephritis
Hypersensitivity reaction to drug,
days after exposure,
fever, rash, haematuria, proteinuria, eosinophilia.
