Renal Flashcards
What characterizes Renal dysplasia?
Undifferentiated Tubular Structures surrounded by primitive mesenchyme, sometimes with heterotropic tissue such as smooth muscle and cartilage
What does renal dysplasia result from?
metanephric differentiation
What are the subtypes of RENAL DYSPLASIA?
Aplastic
Multicystic
Diffuse Cystic
Obstructive
What is the most common cause of an abdominal mass in newborns? What otheer mass can be palpated in newborns with this disease?
Unilateral multicystic renal dysplasia
Flank mass
What characterizes Medullary sponge kidney?
Multiple small cysts in the renal papillae
What are the symptoms of AD PKD?
Heaviness in the loins B/L Flank Mass Passage of Blood Clot in the Urine Azotemia 1/2 progress to uremia (clinical renal failure)
Morphological changes in what part of the kidney do the following syndromes share in common (Amyloid nephropathy, FSGS, Hereditary Nephritis, Membranous glomerulopoathy)?
Glomeruli
What causes Amyloid Nephropathy?
Deposition of secreted lambda or kappa light chains in the glomerular basement membranes and mesangial matrix. Amorphous acellular material expands the mesangium and obstructs the glomerular capillaries.
The immunoglobulin chains are secreted by neoplastic plasma cells.
Where else other than GBM can deposits of AL amyloid appear?
Tubular Basement membranes
Walls of Renal Vessels
Amyloid deposits are identified by? not identified by?
Congo Red apple-green
Not PAS - it is not PAS positive
What does Renal amyloidosis lead to ?
Nephrotic Syndrome
Renal Failure
What characterizes MCD?
Fusion (effacement) of visceral epithelial foot processes on EM (from cell selling as seen in all cases in nephrotic range proteinuria)
Normal glomeruli in light microscopy
Where are granular deposits found in the glomeruli of patients affected by Membranous proliferative glomerulonephritis?
Glomerular capillary Loops and Mesangium
What are the range of possible prognosis of membranous glomerulonephropathy?
Spontaneous Remission (25%) Persistent proteinuria and stable/partial loss of renal function (50%) Renal Failure (25%)
Subendothelial deposits of immune complexes are found in what diseases?
Lupus Nephritis
Membranoproliferative glomerulonephritis
What might distinguish membranous nephropathy due to lupus from idiopathic membranous nephropathy?
Membranous nephropathy of lupus also features mesangial and subendothelial deposits of immunogloobulins. (not just along BM)
Granulomatous lesions resulting from Wgener granulomatosis can be found where in the body?
The nose, sinuses, lungs, and is associated with renal glomerular disease
Wegner granulomatous necrotic lesions are characterized by?
Parenchymal necrosis
Vasculitis
Granulomatous inflammation (composed of neutrophils, plasma cells, and macrophages)
What characterizes ANCA glomerulonephritis?
It is an aggressive, Neutrophil-mediated disease characterized by glomerular necrosis and crescents.
Neutrophils adhere to endothelial cells, release toxic oxygen metabolites, degranulate, and kill the endothelial cells.
Exudation of inflammatory cells through the disrupted, segmentally necrotic basement membrane leads to the formation of the crescents.
In FSGS, what findings are expected upon light microscopy?
Varying numbers of glomeruli with segmental obliteration of capillary loops
( obliteration caused by increased collagen and the accumulation of lipid or proteinaceous material.)
ON renal biopsy, what is the diagnostic findings of Berger Diseaes?
Intense Mesangial staining for IgA often accompanied by C3 staining (activates complement through the alternative pathway)
(There is a range of nephropathies seen on light microscopy: no changes to chronic sclerosing glomerulonephritis)
What groups of diseases demonstrate Focal proliferative glomerulonephritis pathology?
Lupus Nephritis
Nephritis that accompanies several vasculitides, Henoch-Schonlein Purpura, IgA Nephropathy (Berger Disease)
Ultrastructural features of acute postinfectious glomerulonephritis include
Subepithelial dense deposits shaped like ‘humps’.
Deposits are accompanied by mesangial and subendothelial deposits which may be more difficult to find but more important in pathogenesis because of their proximity to inflammatory mediator systems in the blood.
What is Diffuse proliferative glomerulonephritis?
Severe form of lupus nephritis, characterized by widespread involvement of glomeruli and diffuse proliferation of mesangial and endothelial cells and even of epithelial cells.
What is most common complication of SLE?
Nephritis
What are microscopic findings of proliferative glomerulonephritis
EM: Deposits of immune complexes on both sides of the basement membrane, in the mesangial areas, and even inside the capillary loops
Thickened BM of the glomeruli are known as “wire loop” lesions.
90% of patients with what glomerular patholgoy have glomerular crescents(crescentic glomerulonephritis)
Patients with anti-GBM glomerulonephritis
What does Anti-GBM glomerulonephritis typically present with?
Rapidly Progressive Renal Failure
Nephritic Signs and Symptoms
Linear immunofluorescence for Ig G is seen along the GBM
Secondary membranous nephropathy causes
Autoimmune Disease (ex SLE) Infectious Diseases (Hep B) Therapeutic Agents (ex. Penicillamine) Malignancy (Paraneoplastic Syndrome is membranous nephropathy)
What bacteria causes 80% of acute pyelonephritis? What is a typical finding in these cases?
Escherichia coli
Bacteriuria
How do bacteria infect the renal parenchyma in pyelonephritis?
bacteriuria to urine reflux to entry of bacteria through the papillae into the renal parenchyma
What are typical symptoms of pyelonephritis? findings?
Flank Pain, Fever , Chills , Malaise
Gross exam: small white abscess on the subcapsular surface of the kidney
Hyperemic and purulent covered urothelium of the pelvices and calyces
Renal Biopsy: extensive infiltrate of neutrophils in the collecting tubules and IS tiissue.
Leukocyte casts findings support what diagnosis?
Upper urinary tract infection
How does proteinuria develop in a Diabetic patient?
Glycosylation of the serum and matrix proteins present in the GBM induces plasma protein binding and excessive matrix production leadintg to thickening of the GBM. As a result, the GBM has increased permeability to albumin. (Proteinuria occurs 10-15 yrs after onset of diabetes)
Describe the lesions found in Diabetic glomerulosclerosis
They are focal, segmental, nodular, and sclerotic.
These lesions are with in the diffuse and expanded mesangial matrix
What kind of changes are seen in the mesangial area, areterioles and Bowman capsule in a patient with Diabetic glomerulosclerosis?
Nodular widening of the mesangial areas
hyalinization of arterioles
Focal hyaline changes of Bowman capsule
What are typical symptoms of Renal papillary necrosis”?
Fever, urinary colic, severe groin and flank pain
What pathologies does Alport Syndrome typically progress to?
Proteinuria, progressive renal failure , and HTN
All men with the X-Linked syndrome and both sexes with AR disease develop ESRD by ages 40-50
What characterizes Acute tubulointerstitial nephritis?
It’s drug induced hypersensitivity that reflects a cell-mediated immune response. Presents s rapidly progressive renal failure about 2 wks after drug administration. (when D/C drug, patients recover)
it’s characterized by infiltrates of activated lymphocytes (T lymphocytes) and admixed eosinophils (not required to be present for diagnosis), a pattern that indicates a Type IV rxn.
In what settings would B/L Renal Cortical Necrosis occur?
Hypovolemia
Endotoxic Shock
Expected Histopathology of Eclampsia
- uniformly enlarged glomeruli
- swollen endothelial cells (with large irregular vacuoles) that obliterate capillaries
- Bloodless glomerular tuft
- vacuoles in podocytes and mesangium
What are tubular IS cells susceptible to and why?
1) Hypoxia and Anoxia
Because they have a high rate of energy consuming metabolic activity and numerous organelles
2) Nephrotoxicity (some antibiotics, radiograph contrast agents, heavy metals-Hg, organic solvent)
Because they absorb and concentrate chemicals
Describe the gross pathology of a kidney affected by ATN
SWOLLEN KIDNEYS with pale cortex and a congested medulla
no pathologic changes in glomeruli or blood vessels
ATN Histopathology
Focal denudation of the tubular basement membrane
Individual necrotic epithelial cells in the tubular lumina
Nephrosclerosis histopathology
Hyalinized glomeruli
Tubules Atrophic or replaced with Fibrous tissue
Arterioles concentrically hyalinized and thickened with displacement (to periphery) OR loss of smooth muscle cells
In children, Renal Artery Stenosis is likely due to what?
Fibromuscular Dysplasia
What are major causes of HUS? What does HUS mcc?
Escherichia coli (Shiga toxin-producing strains)
MCC of adult kidney cancer? What are the cells of origin? What is associated mutation?
RCC originiates from renal tubules or ductal epithelial cellsb (The tumor is composed of cuboidal cells that form either tubules or solid nests)
Loss of at least one allele of the VHL gene leads to reduced tumor suppression activity
Clear cell (washed away glycogen & fat rich cytoplasm) carcinoma is most common RCC
What does Wilms Tumor consist of?
Embryonal nephrogenic elements (resemble normal fetal tissue): 1.Metanephfri Blastema 2. Immature stroma (mesenchymal tissue) 3. Immature epithelial elements
What is differential for abdominal mass in children?
Wilms Tumor
Neuroblastoma (secretes catecholamines and elevates vanillynandelic acid in the urine)
Multicystic Renal dysplasia
What are the most common lsites of Nephrolithiasis?
pelves and calyces of the kidney for formation and accumulation of calculi
Describe uric acid stones
Smooth, yellow, hard, and radiolucent
Where are the sites of hydronephrosis? what ‘s the progression?
First dilation of hte collecting ducts,
then, dilation of the proximal and distal oconvulted tubules
Grossly, progressive dilation of the renal pelves and callyces occurs, and atrophy of the renal parenchyma ensues
Struvite and Apatite
Precipitation of Magnesium ammonium phosphate and calcium phosphate
They form the Staghorn calculi that fills the eniter epelvis and calices
What renal pathology does MH and Thrombotic Microangiopathy have in common?
Arteriolar fibrinoid necrosis
Arterial edematous intimal expansion,
Glomerular congestion
Vascular Thrombosis
Where in the nephron do sickled cells sicklel often? What does this lead to?
Vasa Recta (site of low oxygen tension) and Glomeruli
Leads to occlusion of lumina and infaction of the medulla and papillae causing when severe, renal papillary necrosis
What pattern is seen in fibromuscular dysplasia?
“string of beads” in angiograms
