Renal - Pathology (2) Flashcards
1
Q
Hydronephrosis
- Definition
- Due to…
- Findings
A
- Definition
- Distention/dilation of the renal pelvis and calyces [A] [B].
- Due to…
- Usually caused by urinary tract obstruction (e.g., renal stones, BPH, cervical cancer, injury to ureter)
- Other causes include retroperitoneal fibrosis and vesicoureteral reflux.
- Findings
- Dilation occurs proximal to site of pathology.
- Only impairs renal function if bilateral or patient only has one kidney.
- Leads to compression atrophy of renal cortex and medulla.
2
Q
Renal cell carcinoma
- Definition
- Due to…
- Findings
- Associations
- Treatment
A
- Definition
- Most common 1° renal malignancy
- Most common in men 50–70 years old
- Due to…
- Originates from proximal tubule cells –> polygonal clear cells [A] filled with
accumulated lipids and carbohydrates.
- Originates from proximal tubule cells –> polygonal clear cells [A] filled with
- Findings
- Manifests clinically with hematuria, palpable mass [B] [C], 2° polycythemia, flank pain, fever, and weight loss.
- Invades renal vein then IVC and spreads hematogenously
- Metastasizes to lung and bone.
- “Silent” cancer because commonly presents as a metastatic neoplasm
- Associations
- Associated with gene deletion on chromosome 3 (sporadic or inherited as von Hippel-Lindau syndrome).
- RCC = 3 letters = chromosome 3.
- Increased incidence with smoking and obesity
- Associated with paraneoplastic syndromes (ectopic EPO, ACTH, PTHrP).
- Associated with gene deletion on chromosome 3 (sporadic or inherited as von Hippel-Lindau syndrome).
- Treatment
- Resection if localized disease.
- Immunotherapy or targeted therapy for advanced/metastatic disease.
- Resistant to chemotherapy and radiation therapy.
3
Q
Renal oncocytoma
- Definition
- Findings
- Treatment
A
- Definition
- Benign epithelial cell tumor (arrows in [A] point to a well-circumscribed mass with a central scar).
- Findings
- Large eosinophilic cells with abundant mitochondria without perinuclear clearing [B] (vs. chromophobe renal cell carcinoma).
- Presents with painless hematuria, flank pain, and abdominal mass.
- Treatment
- Nephrectomy.
4
Q
Wilms tumor (nephroblastoma)
- Definition
- Findings
- Due to…
A
- Definition
- Most common renal malignancy of early childhood (ages 2–4).
- Contains embryonic glomerular structures.
- Findings
- Presents with huge, palpable flank mass and/or hematuria.
- Due to…
- “Loss of function” mutations of tumor suppressor genes WT1 or WT2 on chromosome 11.
- May be part of Beckwith-Wiedemann syndrome or WAGR complex:
- Wilms tumor
- Aniridia
- Genitourinary malformation
- Mental Retardation (intellectual disability).
5
Q
Transitional cell carcinoma
- Definition
- Findings
- Associations
A
- Definition
- Most common tumor of urinary tract system (can occur in renal calyces, renal pelvis, ureters, and bladder) [A].
- Findings
- Painless hematuria (no casts) suggests bladder cancer.
- Associations
- Associated with problems in your Pee SAC:
- Phenacetin
- Smoking
- Aniline dyes
- Cyclophosphamide.
6
Q
Squamous cell carcinoma of the bladder
- Definition
- Risk factors
- Findings
A
- Definition
- Chronic irritation of urinary bladder –> squamous metaplasia –> dysplasia and squamous cell carcinoma.
- Risk factors
- Schistosoma haematobium infection (Middle East), chronic cystitis, smoking, and chronic nephrolithiasis.
- Findings
- Presents with painless hematuria.
7
Q
Acute infectious cystitis
- Definition
- Findings
- Risk factors
- Due to…
- Lab findings
A
- Definition
- Inflammation of urinary bladder.
- Findings
- Presents as suprapubic pain, dysuria, urinary frequency, and urgency.
- Systemic signs (e.g., fever, chills) are usually absent.
- Risk factors
- Female gender (short urethra), sexual intercourse (“honeymoon cystitis”), and indwelling catheters.
- Due to…
- E. coli (most common).
- Staphylococcus saprophyticus—seen in sexually active young women (E. coli is still more common in this group).
- Klebsiella.
- Proteus mirabilis—urine has ammonia scent.
- Adenovirus—hemorrhagic cystitis.
- Lab findings
- Positive for leukocyte esterase (+).
- Nitrites appear for gram-negative organisms (especially E. coli).
- Sterile pyuria and (-) urine cultures suggest urethritis by Neisseria gonorrhoeae or Chlamydia trachomatis.
8
Q
Acute pyelonephritis
- Findings
- Due to…
- Risk factors
- Complications
- Treatment
A
- Findings
- Affects cortex with relative sparing of glomeruli / vessels [A].
- Presents with dysuria, fever, costovertebral angle tenderness, nausea, and vomiting.
- Often presents with white cell casts in urine.
- CT shows striated parenchymal enhancement (arrow in [B])
- Due to…
- Ascending UTI (E. coli is most common), vesicoureteral reflux, and hematogenous spread to kidney.
- Risk factors
- Indwelling urinary catheter, urinary tract obstruction, diabetes mellitus, and pregnancy.
- Complications
- Chronic pyelonephritis, renal papillary necrosis, and perinephric abscess.
- Treatment
- Antibiotics.
9
Q
Chronic pyelonephritis
- Definition
- Due to…
- Findings
A
- Definition
- The result of recurrent episodes of acute pyelonephritis.
- Due to…
- Typically requires predisposition to infection such as vesicoureteral reflux or chronically obstructing kidney stones.
- Findings
- Coarse, asymmetric corticomedullary scarring, blunted calyx.
- Tubules can contain eosinophilic casts resembling thyroid tissue [C] (thyroidization of kidney).
10
Q
Drug-induced interstitial nephritis (tubulointerstitial nephritis)
- Definition
- Findings
A
- Definition
- Acute interstitial renal inflammation.
- Findings
- Pyuria (classically eosinophils) and azotemia occurring after administration of drugs that act as haptens, inducing hypersensitivity.
- Nephritis typically occurs 1–2 weeks after certain drugs (e.g., diuretics, penicillin derivatives, sulfonamides, rifampin), but can occur months after starting NSAIDs.
- Associated with fever, rash, hematuria, and costovertebral angle tenderness, but can be asymptomatic.
11
Q
Diffuse cortical necrosis
- Definition
- Due to…
- Associations
A
- Definition
- Acute generalized cortical infarction of both kidneys.
- Due to…
- Likely due to a combination of vasospasm and DIC.
- Associations
- Associated with obstetric catastrophes (e.g., abruptio placentae) and septic shock.
12
Q
Acute tubular necrosis
- Definition
- Prognosis
- Key finding
- 3 stages
- Due to…
A
- Definition
- Most common cause of intrinsic renal failure.
- Prognosis
- Self-reversible in some cases, but can be fatal if left untreated.
- Death most often occurs during initial oliguric phase.
- Key finding
- Granular (“muddy brown”) casts [A].
- 3 stages:
- Inciting event
- Maintenance phase
- Oliguric
- Lasts 1–3 weeks
- Risk of hyperkalemia, metabolic acidosis
- Recovery phase
- Polyuric
- BUN and serum creatinine fall
- Risk of hypokalemia
- Due to…
- Ischemic injury
- 2° to decreased renal blood flow (e.g., hypotension, shock, sepsis, hemorrhage, CHF).
- Results in death of tubular cells that may slough into tubular lumen [B]
- Proximal tubule and thick ascending limb are highly susceptible to injury.
- Nephrotoxic injury
- 2° to injury resulting from toxic substances (e.g., aminoglycosides, radiocontrast agents, lead, cisplatin), crush injury (myoglobinuria), hemoglobinuria.
- Proximal tubule is particularly susceptible to injury.
- Ischemic injury
13
Q
Renal papillary necrosis
- Definition
- Due to…
- Associations
A
- Definition
- Sloughing of renal papillae –> gross hematuria and proteinuria.
- Due to…
- May be triggered by a recent infection or immune stimulus.
- Associated with:
- Diabetes mellitus
- Acute pyelonephritis
- Chronic phenacetin use (acetaminophen is phenacetin derivative)
- Sickle cell anemia and trait
14
Q
Acute kidney injury (acute renal failure)
- Normal nephron vs. acute kidney injury
- Types
A
- Normal nephron vs. acute kidney injury
- In normal nephron, BUN is reabsorbed (for countercurrent multiplication), but creatinine is not.
- Acute kidney injury is defined as an abrupt decline in renal function with increased creatinine and increased BUN over a period of several days.
- Types
- Prerenal azotemia
- Intrinsic renal failure
- Postrenal azotemia
15
Q
Prerenal azotemia
- Type of condition
- Definition
- Urine osmolality (mOsm/kg)
- Urine Na+ (mEq/L)
- FENa
- Serum BUN/Cr
A
- Type of condition
- Acute kidney injury (acute renal failure)
- Definition
- As a result of decreased RBF (e.g., hypotension) –> decreased GFR.
- Na+/H2O and urea retained by kidney in an attempt to conserve volume, so BUN/creatinine ratio increases.
- Urine osmolality (mOsm/kg)
- > 500
- Urine Na+ (mEq/L)
- < 20
- FENa
- < 1%
- Serum BUN/Cr
- > 20