Cystic diseases of the Cystic diseases of the kidneykidney

Presented By Presented By Prof. Dr.Prof. Dr.

Nabil Tadros MikhailNabil Tadros Mikhail MBBS, MS Pathol., PhD Pathol.MBBS, MS Pathol., PhD Pathol.

Prof. of PathologyProf. of Pathology Alexandria University - EgyptAlexandria University - Egypt

Consultant & Chief PathologistConsultant & Chief Pathologist King Fahad Central Hospital King Fahad Central Hospital

Gizan - KSAGizan - KSA

Cystic diseases of the kidneyCystic diseases of the kidney

• Cystic diseases of the kidney are a Cystic diseases of the kidney are a heterogeneous group inherited in most heterogeneous group inherited in most cases. cases.

• They are important because:They are important because:1.1. They are common.They are common.

2.2. They can be confused with malignant They can be confused with malignant tumors.tumors.

3.3. Some forms as adult polycystic Some forms as adult polycystic kidney are the major cause of CRF.kidney are the major cause of CRF.

1-Simple cysts1-Simple cysts::

• Occur single or multiple.Occur single or multiple.

• Commonly they are 1-5 cm in Commonly they are 1-5 cm in diameter. diameter.

• It is translucent, lined by smooth It is translucent, lined by smooth membrane and filled with clear membrane and filled with clear fluid. fluid.

1-Simple cysts1-Simple cysts: :

MicroscopicallyMicroscopically

• The membrane is composed of single The membrane is composed of single layer of flattened or atrophic layer of flattened or atrophic epithelium. epithelium.

• The cyst is often confined to the The cyst is often confined to the cortex. cortex.

• It is usually asymptomatic ,or may It is usually asymptomatic ,or may produce pain or hemorrhage. produce pain or hemorrhage.

1-Simple cysts1-Simple cysts::

• It can be differentiated from It can be differentiated from renal tumor in three aspects: renal tumor in three aspects:

1.1. Renal cyst has smooth contour.Renal cyst has smooth contour.

2.2. Almost AvascularAlmost Avascular

3.3. It gives fluid rather than solid It gives fluid rather than solid signal on ultrasonographysignal on ultrasonography

Simple single renal cyst

Simple single renal cyst

Multiple simple renal cystsMultiple simple renal cysts

2-Dialysis associated cysts2-Dialysis associated cysts

• Cysts occur in patients with end Cysts occur in patients with end stage renal disease who have stage renal disease who have undergone dialysis for long time. undergone dialysis for long time.

• They are found in both renal cortex They are found in both renal cortex and renal medulla. They may bleed. and renal medulla. They may bleed.

• Occasionally adenoma or Occasionally adenoma or adenocarcinoma arise in their wallsadenocarcinoma arise in their walls..

Cystic changes of chronic renal dialysis. Cystic changes of chronic renal dialysis. kidneys are normal in size. kidneys are normal in size.

Cysts are small in size and not exceed 2 cm in size.Cysts are small in size and not exceed 2 cm in size.

3-autosomal Dominant 3-autosomal Dominant Adult Polycystic Kidney Disease Adult Polycystic Kidney Disease

(APKD)(APKD)

• APKD is characterized by multiple APKD is characterized by multiple expanding cysts of both kidney expanding cysts of both kidney that destroy intervening that destroy intervening parenchyma .parenchyma .

• It account for 10% of cases ofIt account for 10% of cases of chronic renal failurechronic renal failure. .

• It is caused by inheritance of It is caused by inheritance of autosomal dominant genes. autosomal dominant genes.

3-autosomal Dominant 3-autosomal Dominant Adult Polycystic Kidney Disease Adult Polycystic Kidney Disease

(APKD)(APKD)

• In In 90% of cases90% of cases the defective gene is the defective gene is on the on the short armshort arm of of chromosome chromosome 16.16.

• In In the remaining 10%the remaining 10% the defective the defective gene reside on gene reside on chromosome 4.chromosome 4.

APKD ….APKD ….

MorphologyMorphology::

• The kidneyThe kidney may reach may reach large or huge sizelarge or huge size

• Become palpable abdominally. Become palpable abdominally.

APKD ….APKD ….

• Macroscopically:Macroscopically: • The kidney is composed of many The kidney is composed of many

cysts of variable size up to 3-4 cysts of variable size up to 3-4 cm in diameter with no cm in diameter with no intervening parenchyma. intervening parenchyma.

• The cysts are filled with fluid The cysts are filled with fluid which may be clear, turbid or which may be clear, turbid or hemorrhagic.hemorrhagic.

• at autopsy here to at autopsy here to reveal markedly reveal markedly bilaterally bilaterally enlarged kidneys enlarged kidneys in the in the retroperitoneum in retroperitoneum in an adult who died an adult who died from complications from complications of chronic renal of chronic renal failurefailure. .

• This patient had This patient had dominant dominant polycystic kidney polycystic kidney disease disease ((DPKDDPKD).).

APKD;APKD;the kidney is markedly the kidney is markedly

enlarged enlarged and the cysts is large in sizeand the cysts is large in size

APKD: bisected surface APKD: bisected surface (many large cysts are (many large cysts are seen).seen).

• This is a multicystic dysplastic kidney.

• This condition must be distinguished from RPKD because it occurs only sporadically and not with a defined inheritance pattern, though it is more common than RPKD.

• The cysts are larger and variably sized.

• Often, it is unilateral.

• If bilateral, it is often asymmetric.

The microscopic appearance of multicystic dysplastic kidney is characterized by large cysts lined by flattened cuboidal epithelium and an intervening parenchyma that is fibrotic with islands of bluish cartilage and rare glomeruli.

APKD …APKD …

• Microscopic examinationMicroscopic examination::

• It reveal some normal parenchyma It reveal some normal parenchyma dispersed among cysts .dispersed among cysts .

• Cysts may be found at any site of Cysts may be found at any site of nephron from tubules to collecting nephron from tubules to collecting ducts and has atrophic lining. ducts and has atrophic lining.

APKD …APKD …• Microscopic examinationMicroscopic examination:…:…

• There is ischemic atrophy of There is ischemic atrophy of intervening renal tissue .intervening renal tissue .

• Superimposed hypertension or Superimposed hypertension or infection is commoninfection is common

APKD contAPKD cont....

• Clinical pictureClinical picture::

• APKD usually APKD usually does not produce does not produce symptoms until the fourth decadesymptoms until the fourth decade by by which time the kidney is large. which time the kidney is large.

• The most common symptom is The most common symptom is painpain, , which may be sever if hemorrhage which may be sever if hemorrhage occur. occur.

• There is There is palpable abdominal masspalpable abdominal mass. .

• Intermittent hematuriaIntermittent hematuria is common. is common.

APKD cotin..APKD cotin..

• Complication:Complication:

• The most important The most important complications are complications are

1.1.HypertensionHypertension

2.2.Urinary tract infection. Urinary tract infection.

• These complications affect the These complications affect the renal function renal function

APKD cotin..APKD cotin..

• Complication:…Complication:…

• End stage renal failureEnd stage renal failure occur at occur at about age of 50 year. about age of 50 year.

• DeathDeath usually result from usually result from uremia uremia or hypertension .or hypertension .

• Renal transplantation is the only Renal transplantation is the only hopehope. .

4-Autosomal recessive 4-Autosomal recessive (childhood) polycystic kidney(childhood) polycystic kidney

• This is a rare anomaly, that has This is a rare anomaly, that has autosomal recessive inheritance. autosomal recessive inheritance.

• It results from mutation in gene It results from mutation in gene at at chromosome 6.chromosome 6.

• It is usually presented at birth or It is usually presented at birth or young infants. young infants.

4-Autosomal recessive 4-Autosomal recessive (childhood) polycystic kidney(childhood) polycystic kidney

• Kidney show numerous cysts in Kidney show numerous cysts in cortex and medulla cortex and medulla (sponge like (sponge like appearance).appearance).

• There is also multiple cysts in the There is also multiple cysts in the liver which may lead to liver which may lead to congenital hepatic fibrosis .congenital hepatic fibrosis .

• It is fatal disorder.It is fatal disorder.

• This child died soon This child died soon after premature birth at after premature birth at 23 weeks gestation 23 weeks gestation resulted from markedly resulted from markedly diminished fetal urine diminished fetal urine output as a output as a consequence of consequence of polycystic kidney polycystic kidney diseasedisease..

• Note the bilaterally Note the bilaterally enlarged kidneys that enlarged kidneys that nearly fill the abdomen nearly fill the abdomen below the liverbelow the liver. .

• The histological The histological appearance in this case, appearance in this case, coupled with the gross coupled with the gross appearanceappearance.., was , was consistent with consistent with recessive polycystic recessive polycystic kidney disease kidney disease ((RPKDRPKD).).

• Here is a cut section Here is a cut section of a kidney with of a kidney with recessive polycystic recessive polycystic kidney disease kidney disease ((RPKDRPKD). ).

• Note that Note that the cysts are the cysts are fairly small but fairly small but uniformly distributed uniformly distributed throughout the throughout the parenchyma so that parenchyma so that the disease is usually the disease is usually symmetrical in symmetrical in appearanceappearance, ,

• with both kidneys with both kidneys markedly enlargedmarkedly enlarged. .

Microscopic examination of recessive polycystic kidney disease: Microscopic examination of recessive polycystic kidney disease: the cysts fill most parenchyma and is hard to find glomeruli. the cysts fill most parenchyma and is hard to find glomeruli. (sponge like)(sponge like)