Medullary Sponge Kidney

 

A.Introduction 

 

  • Medullary Sponge Kidney is also known as Lenarduzzi Cacchi-Ricci disease
  • It is a congenital kidney defect that affect the tubules of the kidney during the fetal stage 
  • MSK belongs to group of  benign cystic conditions that affects one or both kidneys 
  • Normally ,the urine flows through the tubules as kidney are being formed during the fetal growth ,whereas in medullary Sponge Kidney disease the formed cyst keep up the urine and does not allow it to flow freely  and thus creating a sponge like appearance 
  • This is usually uncommon but can be affected 1 in 5000 people

 

B.What are the possible Causes of Medullary Sponge Kidney disease ?

 

  • The cause of this developmental disorder is not known till date
  • There are certain studies reported that people who develop calcium based kidney stones have medullary Sponge Kidney disease 
  • The disease is more prone in females than males



C.What are the signs and symptoms of medullary Sponge Kidney disease?

 

The condition is usually asymptomatic  till the patient reaches the age of 20 or till the complications arise , usually at age of 40-50yrs

But the disease can be symptomatic if renal colic , nephrolithiasis, recurrent infections is present.

 

But the signs occur secondary to the above mentioned conditions 

 

  • Urinary tract infection
  • Renal stones
  • Difficulty during urination
  • Burning sensation
  • Discolored urine due to blood or other protein
  • Fever 
  • Nausea
  • Chills
  • Vomiting
  • Polyuria
  • Decreased renal ability to concentrate and impaired urine acidification 
  • Bone metabolic defects 
  • Other Infections 

 

D.How does the condition contribute to stone formation?

 

  • The disease is characterized by ectasia of papillary collecting ducts in both or single kidney
  • Due to this, the urine stasis occurs in the dilated ducts which further causes hypocitraturia which is an situation where the incomplete distal tubular acidosis is happened which contributes to the formation of calcium containing calculi 



E.How is it diagnosed?

 

  • The diagnosis is based upon the proper take up of family history and medical history along with physical examination to rule out known or unknown disease 
  • The alternative way is through imaging studies 
  • The various imaging techniques include CT scan , intravenous pyelogram, ultrasound 
  • This procedures is only done when the patient have positive family history or recurrence of urinary tracts infections or renal stones
  • The intravenous pyelogram usually shows up the blocked tubules in kidney or even clusters of cysts
  • Ultrasound identifies the renal stones or any other related deposits
  • CT scans helps to evaluate the dilated or shrunken tubules or kidney 
  • Ultrasonography shows hyperdense papillary with clusters of small stones.

 

F.How do we treat  the disease ?

 

  • There is no alternative way to reverse the condition but can be supported with the usage of medications,following diet and through controlling existing infections .
  • The expert focuses on to cease the spread or other futuristic infections from happening
  • If patient is asymptomatic,no treatment is required except the supportive therapy .If recurrence then metabolic evaluation is required 
  • The first step includes treating Urinary tract infections by Antibiotics according to the patient’s history,condition and the type of bacteria caused 
  • Secondly if patient has kidney stones ,treated is provided based on the signs, symptoms and size of the stones
  • Smaller stones can pass through urine without any requirement for surgery .Still, the patient need supportive therapy and analgesic medications 
  • The larger stones are removed by performing surgery immediately
  • The surgical procedures include Shockwave lithotripsy, ureteroscopy, percutaneous nephrolithotomy .
  • The medications include low dosage antibiotics to prevent infections and thiazides / potassium citrate
  • Supportive therapy includes drinking plenty of water ,Reduce Animal protein,sodium intake,and maintaining enough Calcium levels.

 

G.How did it appear pathologically?

 

  • On gross examination it appears either normal/shrunken /swollen 
  • In microscopic examination the cysts are shown to line up with flattened columnar or cuboidal cells 

 

H.Grading system for risk of  complications based upon imaging study findings

 

Classifications were as follows:

 

  • Grade 1 –  One calyx, unilateral
  • Grade 2 – One calyx, bilateral
  • Grade 3 – More than one calyx, unilateral
  • Grade 4 – More than one calyx, bilateral

 

H.What is the prognosis of medullary Sponge Kidney ?

 

  • Patients can have recurrent nephrolithiasis or kidney stones , which can lead to significant morbidity in patients with MSK
  • Very much rarely, patients may develop renal failure as a result of repeated pyelonephritis or urinary tract obstructions.
  • In approximately 10% of patients with medullary sponge kidney, major morbidity is caused due to  repeated passing of renal stones and by recurrent UTI. 
  • Complete obstruction of the kidney by renal stones is rare. 
  • Surgery isn’t always  required to remove the larger stones because they are usually very small and pass spontaneously



I.Frequently Asked Questions 

 

1.What does medullary Sponge Kidney disease mean?

 

  • It is a congenital medical condition related to the kidney.This birth defect affects the tubules or ducts during the fetal development.
  • It is also known as cacchi -ricci disease

 

2.Is medullary Sponge Kidney serious?

 

Medullary Sponge Kidney disease is not serious .It hardly leads to seriousness .Some common complications include hematuria ,renal calculi,Recurrent urinary tract infections.If untreated or delayed can lead to chronic kidney disease and end up in kidney failure.Along with renal stones other associated risk factors include hypocitraturia, hypercalciuria, hyperuricosuria, hyperoxaluria

 

3.Is medullary Sponge Kidney curable?

 

No, Medullary Sponge Kidney disease is not curable and there is no cure for this.The only way left is to relieve the associated signs and symptoms .It becomes too late until the disease is exposed until or unless there is an infection or stones  which are manageable

 

4.Can Medullary Sponge Kidney be seen on CT?

  • Yes,In medullary sponge kidney (MSK), unenhanced CT scan findings may be normal or demonstrate medullary nephrocalcinosis. 
  • Enhanced scans may demonstrate contrast accumulation within the papillae.
  • Also helps in detecting the dilation of tubules caused due to any obstructions

 

5.Is Medullary Sponge Kidney genetic?

 

  • Most of the cases run sporadically in families without known reason and may be inherited
  • This condition is an Autosomal dominant genetic trait

 

6.Can medullary Sponge Kidney cause high Blood pressure?

 

Yes,due to low perfusion of the kidney the RAAS mechanism gets activated which causes the increased blood pressure.So,there is still a chance for secondary hypertension in medullary Sponge Kidney patients  

 

7.Is Medullary Sponge Kidney the same as polycystic kidney disease?

 

They represent different diseases in the same individual. Medullary Sponge Kidney disease might be a precursor of Polycystic Kidney disease 



8.Can you get disability for Medullary Sponge Kidney?

 

No,MKD does not get disability but Medullary Sponge Kidney along with renal stones is considered as disability for about 30% pursuant

 

9.what causes medullary Sponge Kidney

 

The etiological reason for medullary Sponge Kidney is unknown till date.There is a connection between the renal stones/UTI’s with MKD 

 

  1. Can kidney cysts go away?

 

Yes, simple cysts go away without treatment ,if presence of them causes symptoms or difficulty to urinate then treatment is required.Upon time the cysts shrinks on their own.

 

11.Which fruit is good for kidney cysts?

 

Citrates containing fruits and grapefruits are known to inhibit the development of cystic growth.

 

12.How do you dissolve a kidney cyst naturally?

 

Yes,heat compressions are recommended to dissolve the cysts .It helps to reduce the thickness of liquid to drain out easily

 

13.Can medullary Sponge Kidney disease cause kidney failure?

 

Yes,if untreated medullary Sponge Kidney disease cause more serious complications like chronic kidney disease and end up in kidney failure 

 

14.When is lithotripsy not recommended?

 

It is not usually recommended for people with chronic Kidney infections because bacteria cannot eliminate completely  from kidneys.It does not  work well with blockage or scar tissues in ureter which prevent from passing the fragments out 

 

15.Appearance of medullary Sponge Kidney disease in intravenous urography?

 

Paint brush like appearance is the characteristic feature which represents the ectatic or dilated collecting tubules 

 

16.How is Medullary sponge kidney disease in children managed ?

 

Children with medullary sponge kidney identified in childhood must be evaluated for other urologic abnormalities and must undergo surveillance for future urologic and abdominal tumors.

 

17.Which congenital abnormalities are associated with medullary Sponge Kidney?

 

Can occur in association with other congenital diseases such as

 

  • Polycystic Kidney disease 
  • Beckwith-Wiedemann syndrome
  • Congenital hemihypertrophy – 10% of patients with hemihypertrophy have medullary sponge kidney,25% of patients with medullary sponge kidney have hemihypertrophy
  • Distal renal tubular acidosis
  • Anodontia 
  • Ehlers-Danlos syndrome
  • Marfan syndrome
  • Renal artery stenosis
  • Ureteral duplication
  • Pyloric stenosis 

 

When associated with medullary sponge kidney, Beckwith-Wiedemann syndrome (enlarged kidneys, medullary sponge kidney, and hemihypertrophy) has a high tumor rate, especially Wilms tumor, adrenal gland cancer, and hepatoblastoma.

 

18.Is medullary Sponge Kidney fatal?

 

Maybe ,it basically takes several months or years to rule out the condition and approach with further treatment.If a patient receives treatment early then the symptoms are relieved if not the condition worsen leading to a kidney failure or irreversible damage.So,it totally depends on the stage/duration  of diagnosis and treatment.

 

19.How does medullary sponge kidney affect the body?

 

As we already knew that kidney play a prominent role in our life by eliminating waste products from our body in the form of urine .As there is a congenital defect in these structures ,this cystic disease holds up the urine to pass through ducts/tubules freely.So,the function is compromised leading to enlarged kidneys  with associated signs and symptoms.

 

20.Does a sponge kidney cause pain?

 

Yes,the pain is caused by any obstruction in the renal tubules while passing stones or by any means of infections/inflammation in and around the area.

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