Renal Pathology Flashcards
What is the likely diagnosis for a patient with a history of tophaceous gout who experiences flank pain and hematuria with no noted radiographic abnormalities?
Uric acid stones, which are not visible on x-ray films (radiolUcent); may be minimally visualized with either CT or ultrasound
A child presents with edema. Urinalysis is positive for 3+ protein. Further evaluation reveals gonadal dysgenesis and a renal mass. What genetic abnormality is likely present?
Loss-of-function mutation in the WT1 tumor suppressor gene (chromosome 11), which is found in Denys-Drash syndrome
What 2 conditions commonly lead to chronic pyelonephritis because they predispose individuals to infection?
Vesicoureteral reflux, chronic obstruction by kidney stones
What are the 4 most common renal stones, in descending order of prevalence
Calcium (80%, especially calcium oxalate), ammonium magnesium phosphate (15%), uric acid (5%), and cystine
In a patient with a urine osmolality < 350, Na+ > 40, FENa > 2%, BUN/Cr > 15, and postvoid residual urine of 125 mL, what type of acute kidney injury is the likely cause?
Postrenal azotemia (the key is the postvoid residual value which should be near zero normally)
How does the glomerular filtration rate (GFR) change in a patient with intrinsic renal failure?
GFR decreases as a result of fluid backflow caused by obstructing necrotic debris in the tubules from acute tubular necrosis (patchy necrosis)
What are 3 possible treatments for stress incontinence?
Weight loss, Kegel exercises to strengthen pelvic floor muscles, pessaries
Which type of nephrotic syndrome may be caused by antibodies to phospholipase A2 receptors?
Primary membranous nephropathy
What are the 2 characteristic findings of focal segmental glomerulosclerosis on light microscopy?
Segmental sclerosis and hyalinosis of glomeruli
What are 8 key clinical consequences of renal failure?
Metabolic Acidosis, Dyslipidemia (↑TG), Hyperkalemia, Uremia, Na+/H2O retention, Growth retardation/developmental delay, EPO deficiency, Renal osteodystrophy (MAD HUNGER)
An otherwise healthy 36-year-old woman presents with resistant hypertension and a bruit over the right flank. Where would you expect to see stenosis on angiography?
Within the distal two-thirds or segmental branches of the right renal artery, a classic presentation of renal artery stenosis due to fibromuscular dysplasia
Obstetric catastrophes (eg, placental abruption) and septic shock are both associated with which serious renal pathology?
Diffuse cortical necrosis
What is the most common treatment for a suspected renal oncocytoma?
Surgical resection (to rule out a true malignancy, especially renal cell carcinoma)
What finding on urinalysis distinguishes gram-negative bacteria from gram-positive bacteria?
The presence of nitrites indicates the presence of gram-negative bacteria (ie, Enterobacteriaceae)
What action is most useful in both treating and preventing kidney stones?
Fluid intake (adequate hydration)
In a patient with uric acid kidney stones, what are 2 treatment options?
Allopurinol and urine alkalinization
What are the typical responses of primary minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and membranous nephropathy to steroid therapy?
Primary (idiopathic) MCD has an excellent response, FSGS has an inconsistent response, and membranous nephropathy has a poor response
What are the 2 most common treatment options for acute simple cystitis?
Trimethoprim-sulfamethoxazole (TMP-SMX), nitrofurantoin
A patient with sepsis becomes hypotensive and develops progressive oliguria. Urinalysis shows muddy brown casts. What is the likely cause of this renal pathology?
Decreased renal blood flow, causing ischemic damage to tubular cells (ischemic acute tubular necrosis)
Diffuse cortical necrosis is thought to be related to a combination of which 2 pathologic processes?
Disseminated intravascular coagulation and vasospasm
What immunofluorescence findings are typically associated with focal segmental glomerulosclerosis?
Immunofluorescence is often negative, although it may be positive for nonspecific focal deposits of IgM, C3, C1
In a patient with intrinsic renal failure, what is the expected urine osmolality, urine Na+, fractional excretion of sodium (FENa), and blood urea nitrogen/creatinine (BUN/Cr) ratio?
Urine osmolality < 350 mOsm/kg, urine Na+ > 40 mEq/L (i.e., failure to concentrate urine); FENa > 2%, BUN/Cr ratio < 15 (i.e., failure to reabsorb)
What is the blood urea nitrogen/creatinine ratio in a patient with intrinsic renal failure? Why?
< 15; Kidneys are not able to reabsorb urea so it remains in the urine leading to a reduced blood urea nitrogen to creatinine ratio
A patient receiving long-term hemodialysis has multiple anechoic cortical/medullary cysts detected by bilateral renal ultrasonography. What 2 mutations may cause this disease?
Mutations in PKD1 (chromosome 16, ~85% of cases) or PKD2 (chromosome 4, ~15% of cases) can cause autosomal dominant polycystic kidney disease
