Short Quiz on Renal Stones/ Nephrolithiasis
2. There is 1 Mark for each correct Answer
Chandu, a 45 yrs male shows calcification on the Rt side of his abdomen in an AP view. In lateral view the calcification is seen to overlie the spine. Most likely diagnosis is:
Ans.C. Renal stones
Opacities on a plain X-ray that may be confused with renal calculus-
- Calcified mesenteric LN.
- Gallstones or concretion in the appendix.
- Tablets or foreign bodies in the alimentary canal (e.g.cyclopenthiazide).
- Ossified tip of the 12th rib.
- Phleboliths: calcification in the walls of veins, especially in the pelvis.
- Calcified tuberculous lesion in the kidney.
- Calcified adrenal gland.
Most ureteral calculi pass and do not require intervention. Spontaneous passage depends on stone size, shape, location, and associated ureteral edema (which is likely to depend on the length of time that a stone has not progressed).
Ureteral calculi 4–5 mm in size have a 40–50% chance of spontaneous passage. In contrast, calculi >6 mm have a The vast majority of stones that pass do so within a 6-week period after the onset of symptoms.
Percentage of renal stones which are radio opaque ‑
Ans. is `d’ i.e. 90%
Although 90 percent of urinary calculi have historically been considered to be radiopaque, the sensitivity and specificity of KUB radiography alone remain poor (sensitivity: 45 to 59 percent; specificity: 71 to 77 percent).
KUB radiographs are useful in the initial evaluation of patients with known stone disease and in following the course of patients with known radiopaque stones.
All of the following types of Renal Stones are Radiopaque, Except:
Answer is B (Uric Acid):
Uric acid stones are characteristically Radiolucent
Ans. C: Staghorn
Even a very large staghorn calculus may be clinically silent for years until it signals its presence by hematuria, urinary infection or renal failure
- Calcium stones (calcium oxalate and calcium phosphate) makes up 75-85% of the total renal calculi
- Uric acid stones are radiolucent
- Uric acid stones are MC in men
- Struvite stones:
– Occur mainly in women or patients who require chronic bladder catheterization
– Result from UTI with urease producing bacteria (proteus spp.)
– Grow in infected urine
- Cystine stones are hard to break in ESWL
The morphology of urine crystals shown in the picture above represents florets of crystal. Hence, calcium phosphate is the most probable renal stone.
All are indicated in a patient with cystinuria with multiple renal stones except
Ans. a. Cysteamine
- Patient with cystinuria with multiple renal stones should be treated with increase urine volume (high fluid intake), alkalinization of urine Penicillamine and tiopronin.
- Inheritance: Autosomal recessive
- Molecular defect: Shared dibasic cystine transporter SLC3A1, SLC7A9
- Tissue manifesting transport defect: Proximal renal tubule, jejunal mucosa
- Individual substrate: COLA (Cystine, Ornithine, Lysine, Arginine)
- Clinical features: Cystine nephrolithiasis
- Increase urine volume (high fluid intake)
- Alkalinization of urine
- Penicillamine and tiopronin undergoes sulfhydryl-disulphide exchange with cystine to form mixed disulphides, since these disulphides are much soluble than cystine, pharmacologic therapy can prevent and promote dissolution of calculi
Ans:A.) Present in alkaline urine
Staghorn/Struvite Renal Calculus
- Upper urinary tract stones that involve the renal pelvis and extend into at least 2 calyces are classified as staghorn calculi .
- Approximately 75% are composed of a struvite-carbonate-apatite matrix. Struvite is magnesium ammonium phosphate.
- Struvite stones are also known as triple-phosphate (3 cations associated with 1 anion), infection (or infection-induced), phosphatic, and urease stones.
- Struvite stones are invariably associated with urinary tract infections. Specifically, the presence of urease-producing bacteria, including Ureaplasma urealyticum and Proteus species (most common), Staphylococcus species, Klebsiella species, Providencia species, and Pseudomonas species, leads to the hydrolysis of urea into ammonium and hydroxyl ions.
- Two conditions must coexist for the formation of struvite calculi. These are (1) alkaline urine (pH >7.2) and (2) the presence of ammonia in the urine. This leads to magnesium ammonium phosphate and carbonate apatite crystallization.
Most kidney stones are made of calcium compounds, especially calcium oxalate.
Which of the following are hardest renal stones
- Cysteine stones are the hardest stones
- They are hexagonal crystals in shape
Answer- D. 80
Routine use of noncontast CT Scan has completely revolutionized to imaging evaluation of renal stone disease, nearly completely replacing plain radiogrpahs and X urography for diagnosis of acute ureteral obstruction by renal stones.
Nephrolithiasis refers to the presence of calculi in the renal collecting system.
Nearly 10 % of the population will form a renal stone in their lifetime.
Sufficient calcium oxalate and phosphate is present in 80 % of the renal calculi for them to be radio-opaque on the plain radiographs.
Renal stones which are laminated and irregular in outline are
Answer- B. Calcium oxalate
Calcium oxalate stones – Usually single, hard (aka Mulberry stone) –
- Dark colored d/t staining with altered blood.
- On section Wavy concentric laminae.
- There may be secondary phosphate deposit on surface.
- High calcium content.
- The patient’s history of recurrent urolithiasis with calcium containing stones is a disorder in regulation of calcium concentration.
- Hyperparathyroidism is associated with production of hypercalcemia, hypercalciuria and finally renal stones