Urology Annals
About UA | Search | Ahead of print | Current Issue | Archives | Instructions | Online submissionLogin 
Urology Annals
  Editorial Board | Subscribe | Advertise | Contact
Users Online: 288   Home Print this page  Email this page Small font size Default font size Increase font size


 
Table of Contents
LETTER TO EDITOR
Year : 2015  |  Volume : 7  |  Issue : 1  |  Page : 129  

Medullary sponge kidneys and the use of dual-energy computed tomography


Department of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA

Date of Web Publication6-Jan-2015

Correspondence Address:
Wisit Cheungpasitporn
Mayo Clinic, 200 First Street SW, Rochester, MN, 55905
USA
Login to access the Email id


DOI: 10.4103/0974-7796.148666

PMID: 25657567

Rights and Permissions

How to cite this article:
Cheungpasitporn W, Erickson SB. Medullary sponge kidneys and the use of dual-energy computed tomography. Urol Ann 2015;7:129

How to cite this URL:
Cheungpasitporn W, Erickson SB. Medullary sponge kidneys and the use of dual-energy computed tomography. Urol Ann [serial online] 2015 [cited 2020 May 27];7:129. Available from: http://www.urologyannals.com/text.asp?2015/7/1/129/148666

Sir,

Since intravenous urography is not performed as often as it used to, medullary sponge kidney can be missed easily. Hereby, we present a 66-year-old female with kidney stones. The analysis of the passed stones was 90% calcium oxalate monohydrate and 10% calcium phosphate. Abdomen CT without contrast showed numerous small bilateral nonobstructive renal calculi at papillary tips suggestive of medullary sponge kidneys. Dual energy CT characterization blue color coding indicated that the stone material was nonuric acid in composition. It is very crucial to recognize the characteristic of medullary sponge kidney in CT scan.

A 66-year-old female presented for evaluation for kidney stones. She did not pass her first kidney stone until the age of 62, at which time she passed 13 stones at once. She denied family history of kidney stones. Her medical history was significant for irritable bowel syndrome, but she denied diarrhea. The analysis of the passed stones was 90% calcium oxalate monohydrate and 10% calcium phosphate. Her blood tests revealed normal creatinine of 0.8 mg/dL. Her urine pH was 6.6. A 24-h urine was supersaturated with hydroxyapatite, otherwise unremarkable. Abdomen CT without contrast demonstrated numerous small bilateral nonobstructive renal calculi at papillary tips suggestive of medullary sponge kidneys [Figure 1]. Dual energy CT characterization blue color coding indicated that the stone material was nonuric acid in composition [Figure 2]. Her kidney stones were not amenable to surgical removal. The patient was informed about her diagnosis and encouraged to keep herself adequately hydrated.
Figure 1: Abdomen CT without contrast demonstrated numerous small bilateral nonobstructive renal calculi at papillary tips suggestive of medullary sponge kidneys

Click here to view
Figure 2: Dual energy CT characterization blue color coding indicated that the stone material was nonuric acid in composition

Click here to view


Patients with medullary sponge kidney usually form apatite (calcium phosphate) in their stones due to their increased urinary pH from incomplete distal renal tubular acidosis (RTA). [1],[2] Calcium oxalate stones can also be developed [3] as in our case presentation. Since intravenous urography is not performed as often as it used to, medullary sponge kidney can be missed easily. For this reason, it is very crucial to recognize the characteristic of medullary sponge kidney in CT scan.

 
   References Top

1.
Goldman SH, Walker SR, Merigan TC Jr, Gardner KD Jr, Bull JM. Hereditary occurrence of cystic disease of the renal medulla. N Engl J Med 1966;274:984-92.  Back to cited text no. 1
    
2.
Morris RC, Yamauchi H, Palubinskas AJ, Howenstine J. Medullary sponge kidney. Am J Med 1965;38:883-92.  Back to cited text no. 2
    
3.
Baggio B, Priante G, Brunati AM, Clari G, Bordin L. Specific modulatory effect of arachidonic acid on human red blood cell oxalate transport: Clinical implications in calcium oxalate nephrolithiasis. J Am Soc Nephrol 1999;10 Suppl 14:S381-4.  Back to cited text no. 3
    


    Figures

  [Figure 1], [Figure 2]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    References
    Article Figures

 Article Access Statistics
    Viewed1596    
    Printed26    
    Emailed0    
    PDF Downloaded215    
    Comments [Add]    

Recommend this journal