Chapter 12

Question 1

lab values for post renal azotemia

Answer 1

During early stage of obstruction, increased tubular pressure “forces” BUN into the blood (serum BUN:Cr ratio > 15); tubular function remains intact (FENa < 1% and urine osm > 500 mOsm/kg).

With long-standing obstruction, tubular damage ensues, resulting in decreased
reabsorption of BUN (serum BUN:Cr ratio < 15),

**THIS IS BECAUSE REABS OF BUN REQUIRES AN INTACT TUBULE

decreased reabsorption of sodium (FENa > 2%), and inability to concentrate urine (urine osm < 500 mOsm/kg).

***ALSO REQUIRES AN INTACT TUBULE

Question 2

Injury and necrosis of tubular epithelial cells (Fig. 12.5); most common cause of acute renal failure aka…

Answer 2

intrarenal azotemia

Question 3

most common causes of ATN

Answer 3

Causes include aminoglycosides (most common), heavy metals (e.g., lead),
myoglobinuria (e.g., from crush injury to muscle), ethylene glycol (associated with oxalate crystals in urine), radiocontrast dye, and urate (e.g., tumor lysis syndrome).

these are nephrotoxic

ischemia can also cause this

Question 4

what is acute interstitial nephritis? what may it progress to?

Answer 4

A. Drug-induced hypersensitivity involving the interstitium and tubules results in acute renal failure (intrarenal azotemia)

B. Causes include NSAIDs, penicillin, and diuretics.

C. Presents as oliguria, fever, and rash days to weeks after starting a drug; eosinophils may be seen in urine.

D. Resolves with cessation of drug

E. May progress to renal papillary necrosis

Question 5

as more water gets reabsorbed in prerenal azotemia….as does…

Answer 5

the BUN

that’s how you get a BUN to creatinine ratio greater than 15

Question 6

PRERENAL AZOTEMIA OFTEN DEVELOPS INTO

Answer 6

ATN aka INTRARENAL AZOTEMIA

Question 7

*WHY are these the lab values for INTRARENAL AZOTEMIA

decreased reabsorption of BUN (serum BUN:Cr ratio < 15), decreased reabsorption of sodium (FENa > 2%), and inability to concentrate urine (urine osm < 500 mOsm/kg)

????

Answer 7

Dysfunctional tubular epithelium!!!!! can’t reabs BUN and can’t really reabs sodium!!!

Question 8

what are angiomyolipomas in the kidney? what are they associated with?

Answer 8

ANGIOMYOLIPOMA
A. Hamartoma comprised of blood vessels, smooth muscle, and adipose tissue
B. Increased frequency in tuberous sclerosis

Question 9

what are renal cell carcinomas associated with?

Answer 9

Paraneoplastic syndromes!!!! (e.g., EPO, renin, PTHrP, or ACTH) may also be present.

Rarely may present with left-sided varicocele

Involvement of the left renal vein by carcinoma blocks drainage of the left spermatic vein leading to varicocele.

Right spermatic vein drains directly into the IVC; hence, right-sided varicocele is not seen.

Question 10

what gene is renal cell carcinoma pathogenesis?

Answer 10

Pathogenesis involves loss of VHL (3p) tumor suppressor gene, which leads
to increased IGF-1 aka insulin like GF (promotes growth) and increased HIF transcription factor (increases VEGF and PDGF).

Question 11

what are the two pathways to get RCC?

Answer 11

Tumors may be hereditary or sporadic.
1. Sporadic tumors classically arise in adult males (average age is 60 years) as a
single tumor in the upper pole of the kidney; major risk factor for sporadic
tumors is cigarette smoke.
2. Hereditary tumors arise in younger adults and are often bilateral.
i. Von Hippel-Lindau disease is an autosomal dominant disorder associated with inactivation of the VHL gene leading to increased risk for hemangioblastoma of the cerebellum and renal cell carcinoma.

Question 12

what is VHL disease?

Answer 12

Von Hippel-Lindau disease is an autosomal dominant disorder associated with inactivation of the VHL gene leading to increased risk for hemangioblastoma of the cerebellum and renal cell carcinoma.

Question 13

what is wilms tumor and how does it present?

Answer 13

Malignant kidney tumor comprised of blastema (immature kidney mesenchyme), primitive glomeruli and tubules, and stromal cells (Fig. 12.20)
1. Most common malignant renal tumor in children; average age is 3 years.
B. Presents as a large, unilateral flank mass with hematuria and hypertension (due to renin secretion)

Question 14

what are the two strange syndromes that Wilms tumor is associated with?

Answer 14

Associated with WTI mutation, especially in syndromic cases

1. WAGR syndrome-Wilms tumor, Aniridia, Genital abnormalities, and mental and motor Retardation
2. Beckwith-Wiedemann syndrome-Wilms tumor, neonatal hypoglycemia, muscular hemihypertrophy, and organomegaly (including tongue)

Question 15

what are the only three bladder cancers that i need to worry about?

Answer 15

• urothelial cancer
• squamous cell carcinoma
• adenocarcinoma

Question 16

risk factors of urothelial cell carcinoma

Answer 16

Malignant tumor arising from the urothelial lining of the renal pelvis, ureter, bladder, or urethra
1. Most common type of lower urinary tract cancer; usually arises in the bladder

B. Major risk factor is cigarette smoke; additional risk factors are naphthylamine, azo dyes, and long-term cyclophosphamide or phenacetin use.

Question 17

which urothelial cell carcinoma is worse- flat or papillary?

Answer 17

Arises via two distinct pathways (Fig. 12.21)

1. Flat-develops as a high-grade flat tumor and then invades; associated with early p53 mutations
2. Papillary-develops as a low-grade papillary tumor that progresses to a high- grade papillary tumor and then invades; not associated with early p53 mutations

Question 18

risk factors of squamous cell carcinoma

Answer 18

Risk factors include chronic cystitis (older woman), Schistosoma hematobium
infection (Egyptian male), and long-standing nephrolithiasis.

Question 19

risk factors of adenocarcinoma of the bladder

Answer 19

Malignant proliferation of glands, usually involving bladder
B. Arises from a urachal remnant (tumor develops at the dome of the bladder), cystitis glandularis, or exstrophy (congenital failure to form the caudal portion of the anterior abdominal and bladder walls)

Question 20

mmmmkay go look over nephritic and nephrotic!! that’s all you can do chica!! remember you are the luckiest girl in the whole world

Answer 20

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