Renal Path Flashcards
If you see red cell casts, where is the blood coming from?
Glomerulous
If you see cellular casts, what has happened?
Acute Tubular Necrosis
What if you see granular casts?
Meh. Less specific.. could be tubular cells, white cells….
What’s this?

Red Cell Cast
Indicates Nephritic Syndrome
What is this?
What does it mean?

White cell cast
Indicates Infection in kidney (because formed cast)
What’s this?
What does it mean?

Lipid cast (with characteristic maltese cross)
Indicates Nephrotic Syndrome
What’s this?
What does it mean?

Epithelial cell cast
Indicates Acute Tubular Necrosis
What might it mean to see broad casts?

Probably Chronic Renal Failure
Azotemia vs Uremia
Azotemia = Increased BUN & Creatinine without disease
Uremia = same, but with disease. can affect any organ
What are the different causes of azotemia or acute renal failure?
- Pre-renal
- Renal
- Post-renal
BUN:Creatinine is >20:1
What is your dx?
Pre-renal Failure
Causes of Acute Pre-Renal Failure?
Sudden hypotension
Decreased perfusion
What is Nephritic Syndrome?
Renal failure with red cell casts
What is Rapidly Progressive Glomerulonephritis?
Nephritic Syndrome + Acute Renal Failure
What is the most common cause of nephritic syndrome?
Post-strep Glomerulonephritis
Cuases of Rapidly Progressive Glomerulo-Nephritis?
-
Anti-GBM
- Goodpasture)
-
Immune Complex
- Post-infx
- SLE
- H-S purpura/IgA nephropathy)
-
ANCA-Associated (aka *pauci-immune *- don’t see anything on immunofluorescence)
- Wegener’s granulomatosis
- Microscopic angiitis
Why do you get edema in nephrotic syndrome?
Lose a lot of protein, albumin decreases with it.
Why do you get hyperlipidemia in nephrotic syndrome?
Liver makes more lipoprotein – trying to compensate for low protein
Will cause lipid cast formation
What if you see lots of eosinophils in a cast?
Probably drug reaction (Acute Intersitial Nephritis)
In what condition do you lose Foot Processes (F)?

Anything with Nephrotic Syndrome
How is it that you can sometimes get hematuria but not proteinuria?
Complex charges (basement mem has GAGs that are negatively charged– keep out proteins)
What stain is this?
What does it show?

Silver stain– shows membranes
What is this? What does it show?

Immunofluorescence– shows immune deposits
Types of Glomerulonephritis
Global: Entire glomerulus
Segmental: Part of glomerulus
Diffuse: >50% of glomeruli are affected
Focal:
Where can immune complexes be depositied in Glomerulonephritis?
Subepithelial (large or small)
Subendothelial
Mesangial
What disease & why?

Diabetic Nephropathy
- thickened GBM
- thickened arterioles
- Arteriosclerosis
What would urine show in patients with Diabetic Nephropathy?
Proteinuria
What are the key morpholic features of diabetic nephropathy?
- Thick GBM
- Mesangial sclerosis

What pattern of sclerosis is pretty specific for Diabetes?
Nodular Glomerulosclerosis

What are two diseases that can cause this?

Diabetes
HTN
What is a complication of diabetes in the kidney?
Infection (pyelonephritis w/ papillary necrosis) due to decreased neutrophil/macrophage function and poor vascular supply
Presentation of Renal Amylodosis?
Proteinuria, then nephrotic syndrome
How can you distinguish amyloidosis from diabetic nephropathy?
Congo Red Stain
What’s this?

amyloidosis
What are the two main causes of amyloidosis?
- Monoclonal lymphoproliferative diseases (multiple myeloma) - AL
- Chronic inflammatory states - AA
Class II Lupus
Mesangioproliferative - like IgA
Hematuria, proteinuria
BUT has full house immunofluorescence
Lupus Classes III & IV are like what?
Membranoproliferative or Post-Infectious (Acute Proliferative) GN
How to you distinguish Lupus Class V (Membranous Glomerulonephritis) from Idiopathic Membranous?
Full house immunofluorscence with Lupus
Where are the deposits in Class II Lupus?
Mainly mesangial
Lupus Nephritis class IV

Hypercellular
Diffuse proliferative
Nephrititc, aggressive
Segmental necrosis
Lupus Class V histo
Spikes!
No inflamm infiltrate
Advanced sclerosis
Subepithelial intramembranous immune deposits

Linear Immune Deposits
Anti-GBM disease:
Abs attacking glomerular BM
Antigen-Antibody complexes most likely get caught WHERE?
Subendothelial (classically, with Lupus)
Nephritic syndrome– what will glomerulus look like?
Hypercellular (usually inflammatory)
Rapidly Progressive Glomerulo-Nephritis (RPGN)
What would you expect to see?
Crescents
Blood in urine. Otherwise healthy. Do biopsy, see this:

Mesangial Hypercellularity – IgA Nephropathy

IgA Nephropathy / Berger Disease
IF: granular mesangial IgA deposition
LM: Mesangial expansion w/segmental sclerosis
IgA nephropathy + vasculitis = ?
Henoch-Schonlein Purpura
Celiac disease– what type of immune nephropathy might you see?
IgA
Rapidly Progressive GN = ?
Nephritic Syndrome + Acute Renal Failure
What is this and what disease?

Crescents
Rapidly Progressive Glomerulonephritis
(would also see large disruptions/gaps in BM)
Anti-GBM: key feature in LM & IF?
- Linear IgG*
- Crescents*
Post-Infectious GN with crescents: good or bad sign?
Bad
RPGN with crescents + vasculitis
Pausi-Immune (negative IF)
ANCA present in serum!
Where do you see this?

Linear IgG
Anti-GBM disease, diabetes, Goodpasture Synd
Can Pausi-immune associated vasculitis affect other organs besides kidneys?
Yes– could be Wegener’s or Polyarteritis Nodosa
What is the classic cause of Nephritic Syndrome?
Post-strep (post-infectious)
Nephritic syndrome: main histologic feature
What will IM show?
Hypercellularity of neutrophils
IM: Granular- huge subepithelial deposits

Agressive Post-Strep Glomerulonephritis would show what histology?
Crescents
Nephrotic Syndrome: What will you always see on EM?
“Loss” of foot processes

Nephrotic Syndrome: Minimal Change
- demographics
- what will you see by LM? IF?
Kids
Normal LM and IF. (Can only see in EM)
Focal Segmental Glomerulosclerosis:
What will you see by LM? IF?
Prognosis?
Clinical S/S?
LM: Focal segmental scarring (can be missed by small bx– will look like minimal change)
IF: Negative
Prognosis: poorer than minimal change
Clinical S/S: hematuria + hypertension
Nephrotic Syndrome: IF shows peripheral granular IgG– what are your first thoughts?
Membranous (others don’t show IF change)
Fatty Casts on urinalysis?
Nephrotic Syndrome
How much proteinuria is needed to be diagnostic of Nephrotic Syndrome?
>3.5 g/day
Focal Segmental Glomerulosclerosis, see this:

Collapsing glomerulopathy
poor prognosis
associated with HIV
See this:

Membranous Glomeronephritis (stage 2)
(BM growing up between deposits)
Lots of proteinuria & hematuria.
Disease?
H&E?
- *Membranoproliferative**: hypercellular, lobulated morphology
- poor prognosis :(
- *Double contours** on BM stain (caused by mesangial cell interposition & immune deposits splitting BM)
- indicative of type I

Type II Membranoproliferative Glomerulonephritis:
histo
serum marker?
Entire glomerular BM is one large dense deposit
C3 Neprhitic Factor in blood!! (keep complement activated)

Biposy of renal failure: scarred glomeruli = ?

Chronic glomerulonephritis
What is it?
Caused by?
Pathogenesis?

Flea bitten kidney + Fibrinoid necrosis
Caused by Malignant HTN
Ischemia of glomeruli -> RAS activation -> further HTN -> further injury

Onion skin Hyperplastic Arteriosclerosis
Long standing malignant HTN
Malignant HTN caused by which kidney?

Little one (renal artery stenosis)
What group of diseases show little thrombi all over the glomerulus?
3 main causes?

Thrombotic Microangiopathies:
- Hemolytic-Uremic Syndrom (HUS)
- Atypical HUS
- Thrombotic Thrombocytopenia
What causes HUS?
Infection of intestinal bacteria (usually E.coli)
toxin (Shiga-like toxin) injure endothelial cells
Present with flu/diarrhea followed by bleeding issues
What causes Atypical HUS?
Hyperactive immunity- can’t turn off complement
What causes Thrombotic Thrombocytopenia?
Functional deficiency of ADAMTS13
causes platelet aggregates (can’t sufficiently cleave VWF)

Hydronephrosis:
caused by obstruction, reflux
Dx? Cause?

Hydronephrosis caused by reflux

Acute tubular necrosis
Epithlelial cell cast
Can be ischemic or toxic
Good prognosis if you get eliminate the causeNext >>

Normal
Dx? Presentation?

Alport Syndrome- multi-layered lamina densa
Present with hematuria, proteinura, hearing loss, vision prob

Thin Basement Membrane Disease
good prognosis (normal fx)

Renal Dysplasia- very cystic, show cartilage
benign, associated with other congential defects

AD-PDK
in adults, common
can get Berry Aneurysm

AR-PKD
kids, rare
Significance?

Dialysis-Assoc: some incr. risk for renal failure
Simple: meh. no.
- What’s this?
What would IF look like? - What’s this?
What would they have in the blood? - What’s this?

- Large sub-epithelial hump
* IF*: granular - Dense Deposit Disease (MPGN 2)
* Serum*: C3 Nephritic Factor - Subendothelial Deposit (Lupus)
What’s this?
Presentation?

IgA nephropathy
Mesangial prolif- mesangial IgA
Present with hematuria

Crescents - BAD prognosis
Prognosis? Other organs affected?

Anti-GBM disease
LM: Crescentic glomerulonephritis
IF: linear
Bad prog
Can affect Lung
Dx? What’s in serum?

Crescentic Glomerulonephritis with Vasculitis
(Pauci-Immune)
ANCA in blood!

Hypercellular neutrophils. Post-infectious
More in kids
good prognosis
Granular IgG & C3 deposits

Large cellular glomeruli with neutrophils. Humps seen on right.
Post-infectious

Minimal change disease
Normal LM
IF negative
Loss of foot processes

Focal Segmental Glomerulosclerosis

1: small subepithelial deposits

2: BM starting to grow up between deposits (spikes)

spikes = Stage 2 Membranous

Stage 3:
IF: “STRING OF PEARLS”– peripheral granular
Stage? Presentation of membranous?

4: thick membrane, few deposits
Present with Nephrotic Synd (proteinuria)
Can be seen w/ Lupus class V

Membranous GN

Stage 3- peripheral granular

Membranoproliferative Stage 1

Mesangial expansion into BM–
Membranoproliferative GN type 1

Type 2 Membranoproliferative
large dense glomerulus

C3 Nephritic Factor
- Minimal Change:
- Membranous:
- Lupus
- IgA: where are the deposits?
- T
- Type 2 MPGN?
- Post-Infectious
- Lupus deposits at?
- Amyloid deposited at?
- Amyloid appearance?
- 2 types of amyloid?
- Diseases with amyloid?
- Diabetes EM?
- Thin Basement Membrane Dis

EM:
- Minimal Change: Foot Process obliteration
- Membranous: Subepithelial deposits, spikes by LM
- Lupus: Mesangial deposits
- IgA: Mesangial deposits
- Type 1 MPGN: mesangium, subendothelial
- Type 2 MPGN: one large density
- Post-Infectious: huge subepithelial humps
-
Amyloid: BM, mesangial deposits; skinny fibrils
- 2 types: light chain (AL), chronic inflamm (AA)
- Diseases assoc: Myeloma, Lymphoma, autoimmune
- Diabetes: Very thick GBM, no deposits
- Thin Basement Membrane Dz: Thin BM


Diabetic Nephropathy:
very thick GBM, arteriosclerosis

Thick GBM

Mesangial sclerosis + thick GBM

Nodular Glomerulosclerosis seen in Diabetes

Arteriosclerosis:
Benign HTN, diabetes

Papillary Necrosis
caused by:
- Pyelonephritis + Diabetes
- Pyelonephritis + Obstruction
- Analgesic Nephropathy

Amyloidosis or Diabetes

Amyloid
Class? Presentation? Differential?

Class 2: mesangial proliferation only
Present with hematuria
Looks like IgA nephropathy but full house IF
Type? Presentation? Differential?

Type 3: focal proliferative
Present with Nephritic Syndrome
Like Membranoproliferative but full house IF
Almost all glomeruli look like this.
Class?

Lupus Nephritis Class 4

class 4
Class?
Presentation?
Differential?

Class V: membranous
Present as Nephrotic
Looks like Idiopathic Membranous GN Full house IF

Benign HTN
arteriosclerosis– granular appearance
Also can be caused by diabetes

Malignant HTN
Arteriolar Necrosis, petichial hemorrhage, onion skin arterioles

Little one (hypoperfused, increases renin)
Dx? Causes?

Thrombotic Microangiopathy
Caused by:
TTP: no ADAMTS13 (cleaves vWF)
HUS (food poisoing- toxin damages endoth cells)
Atypical HUS (Factor H)

Pyelonephritis
usually from cystitis (ascending)
Fecal flora
can also be from hematogenous spread

Papillary Necrosis
- Analgesic Nephropathy + Diabetes
- Pyelonephritis + Diabetes
- Pyelonephritis + Obstruction

Chronic Pyelonephritis
blunted calices
2 main causes: obstruction, reflux
Obstruction - diffuse
Reflux- @ poles

Xanthogranulomatous Pyelonephritis
can look like renal cell carinoma
usually from Proteus
Dx? Cause? Urinalysis?

Drug-Induced Interstitial Nephritis
NSAIDs, diuretics, abx…
Eosinophil cast

Meyloma Light Chain casts

Clear Cell Renal Cell Ca
assoc w/VHL mutation

Sarcomatoid Renal Cell CA
bad prognosis

Renal Vein invasion

Oncocytoma
Scar
Granular eosinophilic cells
Mitochondria
Benign

Chromophobe Renal Cell Carcinoma
Distinct membranes, large perinuclear halos, vesicles
Colloidal Fe +
Dx? associated with?

Angiomyelolipoma
associated with Tuberous Sclerosis
usually benign

Medullary Fibroma
common, benign
Baby with this tumor

Wilms.
Solid (not renal dysplasia), necrosis

Blastema: small round cells
Epithelium: tubule formation
Stroma: loose spindle cells

Wilm’s tumor
primitive glomerular structures (lef)
Blastema

Blastmea
Epithelium

ANAPLASIA- bad prognosis

Urothelial Carcinoma (transitional cell ca)

Papilloma
benign

Inverted papilloma
benign

Low Grade Papillary Urethelial Carcinoma
rarely invades or metastasizes

High-grade urothelial carcinoma
necrosis, ugly nuclei

Urothelial CA in situ
Flat red patch grossly
Likely to invade
Positive cytology
Country association?

Squamous Cell Carcinoma
schistomiasis
EGYPT!!!

Hyperacute Rejection:
pre-formed antibodies
Thrombosis of vessels -> necrosis

Acute Rejection:
Tubulitis
(Vasculitis)

Chronic Rejection
Fibrosis
Thick vessels
Transplant Glomerulopathy: (lamina rara interna thickening)
2 most common causes of this

Diabetes
Hypertension
What is the basic mechanism of Hyaline Arteriosclerosis in hypertension?

Endothelial cell damage
If you don’t form ONE kidney - prognosis?
BOTH?
Unilateral kidney agenesis- okay
Bilateral- stillborn
Small, shrunken kidney. How can you tell if its congenital or acquired?
Prognosis?
Count the papillae… < 6 = hypoplasia
Unilateral is good prognosis
Bilateral -> renal failure
Common location of ectopic kidney?
Pelvis
Horshoe kidney: prognosis?
No
Double ureter: problem?
Meh. no.
Cystic abdominal mass in newborn?
Renal Dysplasia
fairly common
unilateral: good prog
bilateral: renal failure
Key histological feature of Cystic Renal Dysplasia?
Cartilage!

AD-PKD:
demographics
Bilateral or unilateral?
Complications?
Location?
Common; in adults
Large cysts
***Bilateral!!!!! (if unilateral, think Cystic Neoplasm)
Associated with Berry Aneurysms!
Everywhere
AR-PDK
Demographics?
Complication?
Location?
Rare, in CHILDREN
Always Bilateral; small cysts (Spongiform Kidney)
Liver involvement (congenital hepatic firosis)
@ Collecting Duct ONLY
Alport’s Syndrome:
- presentation
- genetics
- Key histological feature on EM
- Hematuria (later proteinuria, nephrotic synd)
May also have deafness or eye probs - XD mutation for Type IV collage
- Layering of Lamina Densa in BM
Thin Basement Membrane Lesion
(Benign Familial Hematuria)
- Genetics?
- Prognosis?
- Familial, asymptomatic hematuria
- Mutation in Type IV collagen (a5)
- Normal renal function if heterozygous
What causes hyperacute rejection?
Pre-formed antibodies
Somebody fucked up at the lab
Causes very quick necrosis
Most common finding in Acute Rejection?
Diagnosis?
Timeframe?
Tubulitis- interstitial inflammation, maybe vasculitis
IF: C4D!
Can occur at ANY TIME
Chronic rejection:
Timeframe?
Findings?
Years
See fibrosis, thick vessels, thick GBM (transplant glomerulopathy)
Transplant Glomerulopathy:
Type of rejection?
What structure is affected?
Chronic rejection
Lamina Rara Interna
Bladder: Malignant cytology, but no mass- just red lesions. What is it?
Is this bad?
Carcinoma in situ
Frequently invades

What is the #1 cause of urolithiasis?
Dehydration!!!!
What’s the most common composition of stones?
What if the stone is hugeeeee?
Calcium
Huge stone = staghorn = Magnesium ammonium phosphate
Uricemia is associated with what diseases?
Gout
Cancer (lymphoma, leukemia)
What is it? Cause?

Staghorn stone: caused by proteus infection
Most common kidney tumor in adults?
Presentation?
Renal Cell CA
Big cystic mass
Most common renal cancer in kids?
Wilm’s
Metastatic disease. Where is it likely coming from?

Kidney (clear cell carcinoma)
What is this? Associated gene mutation?

Clear Cell Renal Carcinoma
associated with Von HIppel Lindau
Chromophobe Renal Cell Carcinoma:
What are the structures seen in EM?

Cytoplasmic Vesicles
Kidney tumor. looks like this:
Prognosis? Invason?

Sarcomatoid (spindle cell) Renal Cell Carcinoma
Poor prognosis
Invade bone, lungs, veins
Renal Cell Carcinomas: paraneoplastic syndromes?
HTN
Hypercalcemia
Polycythemia
Hepatic dysfx
Oncocytoma vs. Chomophobe RCCa
Oncocytoma: scar, granular cells, Colloid Fe stain (-), benign, mitochondria
Chromophobe RCC: halos, Coll. Fe (+), malignant, vescicles

Patient with tuberous sclerosis. Find tumor in kidney. What is it most likely?
Angiomyolipoma

3 Components of Wilms Tumors
- Blastema (small cells)
- Epithelium (forming tubules)
- Stroma (loose spindle cells)
What is a marker of poor prognosis in Wilms Tumor?
Anaplasia
- large pleimorphic hypechromatic nuclei (3x normal size)
How can you tell that this is Wilms Tumor instead of Renal Dysplasia?

Wilms tumor is solid
(Renal dysplasia is cystic)
1 symptom?
Urinalysis?

Urothelial tumor (aka Transitional Cell Ca)
Hematuria with FRESH RBCs (not casts)
1 risk factor of Urithelial tumor?
SMOKING
Male, elderly
Chronic bladder irritation causes what kind of tumor?
Squamous cell carcinoma

papilloma

Inverted urothelial papilloma

High Grade Urothelial Carcinoma
papillary & solid architecture
- necrosis (yellow)
frequently invade
How can you get Invasive Carcinoma from normal urothelial tissue?
Normal –> Carcinoma in situ –> Invasive Carcinoma
OR
Normal –> Low grade CA –> High grade CA –> Invasive CA