Kidney Diseases

Multicystic not polycystic amended question

04/28/2005 09:29AM

Question:

My previous question was: I just had my 20 week level II ultrasound. Everything was normal (amniotic fluid included), except for the right kidney was multicystic. Left kidney was normal per the Dr. The Amnio came back normal as well.
I am scheduled for another appt in 4 weeks to check to see if the other kidney is still normal and to check on the affected kidney
My question is: after the 20 week mark, how often is it that a kidney that looks completely normal may change to multicystic? Would it have already occurred? And the answer was: Answer: The disorder of polycystic kidney has many different meanings. It would be possible for your kidney to be moved by your pregnancy and appear different than before. One or more small cysts on one surface of the kidney might not have been visible at another stage of your pregnancy. Many disorders of the kidney are labeled polycystic. The prognosis for almost all polycystic disorders is very good. The best person to answer your question would be your primary care provider.

My amended question is related to the fact that Multicystic and PKD are completely different and should not be used as one in the same. The BABY not me is shown to have the kidney problem. Can someone clear this up please? Does anyone know anything about Multicystic Displastic Kidney?
And once seen at 20 weeks as unilateral... does it sometimes appear after subsequent vistis as bilateral?

Answer:

I will try my best to answer your question. I apologize for the misunderstanding. This is the question I will try to clarify, “Does anyone know anything about Multicystic Displastic Kidney? And once seen at 20 weeks as unilateral... does it sometimes appear after subsequent vists as bilateral?” Here is a reference to the National Instituit of Health website (NIDDKD). Below is an excerpt from the article "Multisystic dyplastic kidney disease", which lists several more references which go into a lot of very detailed information.
Sonographic findings: Multicystic dysplastic kidney disease is most common an incidentally finding 1.
The kidney(s) appear(s) enlarged with multiple cysts[3] which are

mostly randomly positioned, but sometimes peripheral;

variable in size and

non-communicating although artifacts may make non-communicating cysts appear as they communicate [4]

The parenchym is seen in small islands between the cysts and the outline of the kidney tends to be lost.

The size of the kidney is proportional to the size and the number of visible cysts 4.

The contralateral kidney needs to be assessed. The contralateral kidney is mostly normal but multicystic dyplastic kidney disease may occur bilaterally or with contralateral agenesis [5], in which there is no functional kidney tissue left and as such the condition is fatal.

If detected in the second trimester the cysts will initially increase in size and number of cysts, followed by involutional changes either in utero or postnatal [6].

Mitchell et al. demonstrated Doppler changes in the peripheral pulmonary arteries in case of multicystic dysplastic kidney disease with pulmonary hypoplasia. The resistance index of the peripheral arteries showed a high resistance pattern. By lack of amniotic fluid lung development is compromised and is incomplete. This results in fewer canaliculi followed by reduced vascularization of the bronchioles and terminal air spaces. The capillary walls are thicker and there is increased resistance. However the permanent changes seen in case of multicystic dysplastic kidney disease seem to give similar waveforms as seen in the temporary changes in case of intra-uterine growth restriction[7].

This reference is copied from the National Institute of Health Web site (NIDDKD) where several detailed references can be found. Please ask your primary care physician for a referal to a board certified Pediatric Nephrologist who would be the best to answer your concerns.

For more information:

Go to the Kidney Diseases health topic, where you can:

Read articles on this topic
Browse the previously asked questions
Ask your own question.

Response by:

Philip W. Hall, 3rd, MD
Professor of Medicine Emeritus
Office of Medical Education
School of Medicine
Case Western Reserve University