1. Renal calculi

2. Renal calculi

3. Presented By
Prof. Dr.
Nabil Tadros Mikhail
MBBS, MS Pathol., PhD Pathol.
Prof. of Pathology
Alexandria University - Egypt
Consultant & Chief Pathologist
King Fahad Central Hospital
Gizan - KSA

4. 

Renal stones is a frequent disorder ,
occur more common in males.
A familiar tendency has been
recognized..

5. 

Pathogenesis:
The cause of stone formation is
often not completely understood ,
but there is many factors involved in
stone formation.

6. Factors involved in stone formation
1.
2.
3.
Increased urine concentration of
stone constituents, so that it exceeds
their solubility in urine (This is the
most important factor).
Decreased urine flow.
Absence of a substance in urine that
inhibit precipitation of salts and
minerals (ex: pyrophosphate)

7. Types of renal calculi

The most important types are:
2.
Calcium oxalates
Calcium phosphate
3.
Magnesium ammonium phosphate
1.
4.
5.
Uric acid
Cystine stone
67%.
8%
15%
8%
2%

8. Etiology of renal calculi
1- calcium stone: It may be due to
A-Hypercalciuria that is not
associated with hypercalcemia(50%).
It is either due to



Increased calcium absorption from gut
(absorptive hypercalciuria) or
Defect in renal reabsorption of Ca
(renal hypercalciuria).

9. Etiology of renal calculi
1- calcium stone: It may be due to
B-Hypercalcaemia (10%) ;
as in cases of

1.
2.
3.
Primary hyperparathyroidism,
Vitamin D toxication,
Sarcoidosis,…

10. Etiology of renal calculi
1- calcium stone: It may be due to


C- Excessive uric acid excretion in
urine:
account for 20% of cases of calcium
stones because uric acid favors
calcium stone formation..

11. Etiology of renal calculi
1- calcium stone: It may be due to



D- hyperoxaliuria 5%.
E- Idiopathic 15%.
Calcium stone occur at any
pH of urine.

12. Etiology,…
2- Magnesium ammonium phosphate stone


It occur in alkaline urine due to
urinary tract infection.
In particular urea splitting bacteria as
proteus vulgaris

13. Etiology,…
3- uric acid stone


It occur in acidic urine due to high
uric acid levels .
Hyperuricaemia may be primary due
to defect in enzyme involved in
purine metabolism (1ry gout)

14. Etiology,…
3- uric acid stone



Hyperuricaemia could be also
secondary (2nd gout).
with increase cell turnover as in
leukemia, chemotherapy and
psoriasis.
Also is seen in cases of decreased
excretion of uric acid as renal failure.

15. Etiology,…
4- Cystine stone


Is genetically defect in renal
transport of cystine .
It is formed in acidic urine

16. Morphology of renal calculi





Calcium stone:
Hard,
Small to medium in size,
Often multiple,
Radiopaque.

17. Morphology of renal calculi




Magnesium ammonium stone:
may be large size
with branching structure
(stag horn stone).
it is radiopaque.

18. Morphology of renal calculi




Uric acid stone
Yellow
Friable
Radiolucent

19. Morphology of renal calculi




Cystine stone
Brown color
May be large
Radiolucent

20. Clinical course of renal calculi




May be asymptomatic.
May present with renal colic
(during its passage into ureter)
Hematuria.
It predispose the patients to urinary
tract infection.

21. Clinical course of renal calculi



Larger stone that cannot
pass will lead to
Obstruction and
produce
1.
2.
hydronephrosis
hydroureter.

22. Clinical course of renal calculi


Diagnosis is done radiological.
Also investigations to detect the
cause is done
1.
2.
3.
4.
Serum calcium
Phosphorus
Uric acid
Para Thyroid Hormone,…

23. The passage of calculus
through urinary tract

24. Hydronephrosis with calculus at ureteropevic junction.

25. Hydronephrosis

26. Causes of hydronephrosis



Hydronephrosis refers to
dilatation of renal pelvis and
calyces with accompanying
atrophy of parenchyma.
Cause by obstruction to outflow of
urine,
The most common causes are:

27. Causes of hydronephrosis




Congenital
Atresia of urethra,
Aberrant renal artery compressing
the ureter,
Renal ptosis with kinking of ureter.

28. Causes of hydronephrosis

Acquired;

Foreign Body: Stones
Tumors: cancer prostate & bladder tumors
Inflammation: prostatitis, ureteritis, urethritis
Neurogenic: spinal cord damage with paralysis



of bladder.

29. 

The unusually high pressure
generated at renal pelvis causes
compression of renal vasculature.
Both artery insufficiency and
venous stasis occur.

30. 
The most severe effects is seen in the
papillae because they are subjected to
the greatest increase in pressure.

Accordingly the Initial functional
disturbances are largely tubular,
Manifested by impaired concentration ability,
Later on glomerular filtration begins to
diminish



31. Morphology :



The kidney is massively enlarged with
greatly distended pelvicalyceal system.
The renal parenchyma is compressed
and atrophied with obliteration of the
papilla and fattening of the pyramids.
Depending on obstruction one or both
ureter may also dilated (hydroureter)

32. Clinical course


Bilateral complete obstruction produce
anuria which need soon medial attention
Incomplete bilateral obstruction produce
polyuria rather than oliguria as a
result of defect in tubular concentrating
mechanism

33. Clinical course




Unilateral hyronephrosis may be silent for
long period unless other kidney is affected.
Bilateral hydronephrosis usually lead to
uremia.
Early removal of obstruction can return the
kidney function.
However with the time the changes become
irreversible.

34. Hydroureter & hydronephrosis

35. Severe hydronephrosis .
.The kidney is markedly enlarged

36. Hydronephrosis affecting mainly the lower pole of kidney
due to stone at this site .The upper pole of the kidney is
normal