What is Medullary Sponge Kidney?

If, for some strange reason, you set out to design a kidney that could form stones as quickly as possible, you might end up with something like a medullary sponge kidney.

 

 

 

Medullary sponge kidney (MSK) is a condition in which a portion of the kidney known as the medullary pyramid is found to have dilated tubules (tubules are small tubes through which urine drains) and numerous small cysts (cysts are fluid filled hollow spaces). The cysts are small, measuring from 1 to 8mm, but are numerous. The cysts give the kidney, when cut, the appearance of a sponge – from which the name of “medullary sponge kidney” was coined. These cysts and dilated ducts lead to poor drainage, making it easier for stones to form. These abnormalities can be seen throughout both kidneys or may be localized in only one part of a kidney. The stones formed in MSK tend to be numerous and scattered throughout the kidney.

How do I know if I have medullary sponge kidney?

Medullary sponge kidney is felt to be non-hereditary (you don’t pass it on to your children). Many patients with MSK never develop problems and don’t know they have the condition. One study estimated that MSK may occur as commonly as 1 in 200 persons while other more conservative estimates report an occurrence rate of 1 in 5,000 to 20,000 persons.

Because many patients with MSK develop no symptoms and remain undiagnosed, reliable data on how many will form stones is not available. In one study of 56 patients from one hospital, the authors reported that 30% of the MSK patients that they studied never developed stones. Among the stone formers, MSK appears to be more common in females and usually first presents in the 30s.

The diagnosis of medullary sponge kidney is made with imaging studies, either with an intravenous pyelogram (an older type of x-ray) or with a contrast CT scan. These imaging studies will show a characteristic distribution of stones or calcifications in the location of the medullary pyramids and contrast pooling in dilated tubules.  In order to confirm the diagnosis, the imaging study should include intravenous contrast in order to demonstrate the dilated tubules that are the hallmark of MSK. However, most CT scans for kidney stones are performed without contrast and in this case the diagnosis, while likely, is not considered definitive because other stone related conditions can also lead to an appearance similar to MSK on a non-contrast CT scan.

Non-contrast CT scan of a  patient with medullary sponge kidney. Multiple stones and calcifications can be seen in both kidneys. To see examples of contrast accumulating in the medullary pyramids of MSK patients on a contrast CT scan or intravenous pyelogram, visit these sites: CT scan or intravenous pyelogram.

What are the symptoms of medullary sponge kidney?

McPhail and colleagues reported that among 56 patients with MSK, the most common presenting symptoms included:

  • Flank pain in 52%
  • Microscopic blood in the urine in 36%
  • Visible blood in the urine in 16%
  • Urinary tract infection in 7%
  • Abdominal pain in 7%
  • Testicular pain in 4%
  • Imaging for other causes in 4%

What type of problems can medullary sponge kidney cause?

Individuals with MSK most commonly present with kidney stones, urinary tract infections, or blood in the urine. In individuals with MSK who form stones, other metabolic abnormalities that predispose someone to form stones are also commonly found, including hypercalciuria (high calcium levels in the urine) and renal tubular acidosis (a disorder with the kidney’s handling of acids).

It therefore appears that just having MSK by itself is not enough to form stones (30% of MSK patients don’t form stones). However, combine the abnormalities found in MSK with someone who has a metabolic tendency to form stones and you will often see an astounding number of stones developing throughout the kidneys.

X-rays for patients with MSK are often impressive for the sheer numbers of stones seen. Not all those stones will necessarily be in a position to drop into the ureter and cause traditional stone symptoms. In order to do so, the stones need to have access to the hollow collecting system portion of the kidney. Instead, many are often embedded in the solid tissue of the kidney (the parenchyma) where they are unlikely to result in a stone passage.

In some patients however, the non-obstructing stones seen in MSK can be associated with significant and chronic pain, even if they are not passing. The pain in this situation can be constant in nature, unlike the episodic pain traditionally seen with kidney stones. It is not certain what causes this pain but authors have proposed that the small numerous stones seen in MSK may cause obstruction of the small tubules and collecting ducts in the kidney, leading to the pain. This pain can be debilitating and treatment is challenging. Narcotic medication, even with large quantities, is often not adequate. Some success with pain control for MSK patients with this type of pain has been reported using laser lithotripsy (see below).

The most common stone types in MSK are calcium oxalate and calcium phosphate.

Thankfully, MSK does not commonly lead to kidney failure.

What can be done about medullary sponge kidney?

Treatment for MSK focuses on prevention and treatment of stones, management of pain, and prevention of infections. There is no treatment available to fix or remove the small cysts and dilated tubules associated with the condition.

In stone formers, maintaining a high fluid intake and treatment with hydrochlorothiazide (to lower urinary calcium) and/or potassium citrate (to raise urinary citrate) are used. Metabolic evaluation with urinary and blood testing can be used to identify specific metabolic abnormalities that increase a person’s risk for stones. In addition, some authors advocate the use of hydrochlorothiazide in all patients with MSK, even when urinary calcium levels are normal.

Treatment for stones that have already formed include the same approaches used for other stone patients, including ureteroscopy, shockwave lithotripsy, or less frequently, percutaneous nephrolithotripsy. Due to the large number of stones formed in MSK and the fact that many of those stones may not be within the collecting system, it is not usually necessary or possible to completely eradicate stones in a patient with MSK.

In patients who have chronic pain associated with MSK, ureteroscopy with laser lithotripsy (called “ureteroscopic laser papillotomy”) may be an option to relieve discomfort. The procedure involves fragmenting and extracting all visible stones in the kidney with the intent to “unplug” and clear obstructed ducts that may have stones trapped in them. In a paper from three institutions, Gdor and colleagues reported on their experience with a total of 65 patients who collectively underwent 176 procedures. All  patients in the study had chronic flank pain and multiple non-obstructing kidney stones. 50 patients had followup information available. The majority of patients who underwent this procedure experienced a reduction in their pain (83%). On average, the duration of pain relief from surgery was 26 months.  Of note, 17 of the patients in the study had a diagnosis of MSK and their pain relief was similar to that seen in non-MSK patients.

If you have been diagnosed with medullary sponge kidney, share your experience or ask a question below.

References:

Campbell-Walsh Urology 10th Edition, 2011.

McPhail and co-authors, “Nephrolithiasis in Medullary Sponge Kidney: Evaluation of Clinical and Metabolic Features”, Urology 2012.

“Medullary sponge kidney” National Kidney and Urologic Diseases Information Clearinghouse, 2008.

Gdor and co-authors, “Multi-Institutional Assessment of Ureteroscopic Laser Papillotomy for Chronic Flank Pain Associated with Papillary Calcifications”, Journal Of Urology 2011.

Editor’s note: This post was updated on 5/15/12  to include more information on diagnosis, pain related to medullary sponge kidney, and treatment options.

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136 Responses to What is Medullary Sponge Kidney?

  1. I actually have a success story to share. I was sent for an ultrasound 3 years ago after experiencing pain under my rib cage. My primary doctor suspected ovarian cysts. During the ultrasound, I remembered that the tech had a really weird look on her face and asked if I ever had trouble walking. At the time I thought it was a very strange question. The same day I get a call from my primary care doctor telling me to call the urologist immediately. I got an appointment the next day. I was in the waiting room when the urologist came in shaking his head. He said there was no way I should be able to stand up straight with this many stones in my kidneys. Now the ultrasound tech ‘s question made sense. We ended up scheduling a uroscopy and subsequent stent (AKA torture device. ) After the procedure, I still had 19 stones in one kidney and 11 in the other. But they were smaller so hopefully nature would take it’s course. I was told this was a condition that I would have to deal with for life and the urological said he would prescribe percoset whenever I needed. After researching. I decided to try lemon essential oils to try to prevent formation of stones. I use it internally everyday. Fast forward to last week and my appoint with the urologist. To his surprise, I had ZERO stones!!!!!!! I told him about the oils and he said urologists are starting to research essential oils as a treatment for MSK. my life has been changed! If anyone would like more info, please feel free to contact me. I am not trying to make money. I think I would get paid 50¢ If anyone orders:) I am also willing to send out samples (I guess the 50¢ would help cover that!) my website is http://mydoterra.com/teachermommy. As my website states, I am a teacher (special educator) and mother to 7 kids. I use oils everyday with my own kids!

  2. Theresa says:

    I was diagnosed with MSK about 8 years ago. I am a stone former. I have gone through some really tough times with this….and also had periods where it have me a break!! Lately have had a not so good time with this. My orogist seems to think people with this should not experience pain unless you have an obstructing stone. Which leaves me feeling untreated and uncared for by my docs….I have left there in tears many times because they don’t seem to even want to understand. All they can see is black and white….either you have an obstructing stone…or not. Going to try a nephrologist next month and see if they have a better understanding of this disease and hopefully be able to help me control the daily pain that I feel at times. It affects your life….the people around you….your family.

  3. Dave says:

    Hello all. I have been diagnosed with MSK and have had severe back pain in my thoracic area for about 8 years now. I’ve never had a stone yet. I was curious where do you all feel your pain at? I’m 28 years old .

  4. Ernie Levon Tuck says:

    Msk is very hard to deal times the pain is sever

  5. Ashelynn says:

    Hi! I just got diagnosed with MSK back in February of this year. I am a 17 year old female with no other family history of MSK. I am an athlete and received my first symptoms of MSK an hour after a soccer game where I had taken a pretty strong hit to my back/kidney region, all of a sudden I was collapsed while talking to my mom screaming in pain. She rushed me to the hospital where they found blood in my urine and did a CT scan on me. The doctor had never seen anything like it when they got my scans back. He came in the room panicked and told my family and I that I had at least 50 kidney stones in my kidneys.  I was later discharged from the hospital that same night and got a referral to go see a urologist. He then read my medical history and reviewed my scans and told me I had Medullary Sponge Kidney Disease and there was “nothing he or I could do about it.” So since then I have been back to the emergency room at least 5-7 times.  each time I go is the same thing.  They get my pain under control, tell me I’m fine and that my levels are fine. And that is probably “just back pain.” The pain I experience is excruciating as I’m sure those of you with MSK already know, but the weird  thing is that I have never passed a single kidney stone I just feel this excruciating pain that starts in my kidneys and makes its way to the front. I have changed my diet, and drink plenty of water. 

    If anyone can help or has any tips for me it would be greatly appreciated since my doctors don’t even know what’s going on. Thank you 

  6. Jessica says:

    I was diagnosed with MSK about 6 years ago (at age 23) when I had my first painful infection. I get an annual ultrasound and take Tamsulosin to widen my tubes when I feel a stone forming. Just had the second major infection in 6 years, so not too bad. My stones are not diet/calcium based so none of the nutritional stuff helps me! I just drink huge amounts of water, even through the night. That seems to make a big difference.

  7. Candice says:

    I saw my Urologist today, although MSK was discussed, he didn’t want to lable it as such yet. I’m am 44 year old female, who passed my first stone when pregnant a 34. My next insident was 3 months ago (10 years later) when I had started passing a stone from my right, and then a week later started passing one on my left. Three months later I’m having pain on my left again. I did have an x-ray and there is one on the left but “very low” in the kidney. I am having pain, the same pain that started 3 months ago. I’m scared of what will happen next, although the x-ray says its no where near its descent. So, what am I feeling? Why am I in pain?

  8. Georgia says:

    my mom was diagnosed with this disease in her late 20′s. she has is now passing very large stones 2-3 times a week with a great deal of pain. I am afraid I have the same problem as I have had three kidney stones all ready and I nearing the age of 30 myself. I wonder if it’s possible to see the cysts on a reg ct scan with no contrast? I have reassured myself that I don’t have the disease because it would have been discovered by this point but now I’m wandering if I do.

    Wish you all the best in you journey with pain control

  9. jude machin says:

    although I was told that msk was only found in the 30-40 age group I first passed a stone at 16 after endless tests because this was happening every few months or even weeks sometimes I had no diagnosis until I was in my 30′s. thankfully the rate I was passing them seemed to slow down for what ever reason, In my 40′s and 50′s I can pass the very small stones with a few hours of not to bad pain and no vomiting I’m due for a ct on sat after quite a lot of years with no monitoring so I’ll share the outcome once I get the results hang in there everyone I’ve had msk for nearly 40 years and still going strong. voltorol suppository 100mg are fantastic I was able to stand upright within 10 mins

  10. Jamie says:

    I want to thank everyone for all the information. My 14 year old daughter was just diagnosed with MSK and has been have severe pain for the last 3 months. We are still trying to figure out a good pain management other than going to ER a lot for iv medication. Any help I can get is appreciated.

    • Nannette says:

      Whatever her stones consist of like mine are calcium salt sugar and potassium just cut back on it have her eat a lot of vegetables and chicken and fish warm baths help and I would suggest a pain medication such as naproxen or a muscle relaxer

    • Marian says:

      I am 66yrs young & was also born with a medullary kidney, diagnosed in my thirties. I was on a low calcium diet for years to help prevent stone formation. Please try to obtain this diet sheet. I have forgotten most of it now.There are some fruits & veg that should NOT be eaten. Spinach, broccoli among them! also foods that you wouldn’t suspect to be harmful. Anything made with flour is one I recall & all dairy except cream for some strange reason. Take care

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