Download - Renal Medullary Cysts
Renal Medullary Cysts
The case of Tobey Montaldo134495
Signalment and History
7 year old MC Golden Retriever Suspect pyelonephritis Microscopic hematuria Isosthenuria Polyuria/Polydipsia Intermittent urinary incontinence
Treatment prior to referral
For treatment of recurrent E. coli UTI
Clavamox for 10 days Amoxicillin for 6 weeks Cephalexin, undetermined duration
Imaging
Ultrasound performed on 7/17/07: possible pyelonephritis; right renal medullary cavitations or cysts—rule out abscess or neoplasia
Imaging
CT scan on 8/29/07: renal corticomedullary or medullary cavitary lesions, bilateral, solitary hepatic cyst
Renal infarcts seen, some associated with cysts
Recheck Ultrasound
Recheck on 1/16/08: slight changes in sizes of cysts, persistent left pyelectasia
Differential Diagnoses for Medullary or Corticomedullary Cysts
Polycystic Kidney Disease Simple renal cortical cysts—degenerative Neoplasia—carcinoma, sarcoma Abscessation Medullary Sponge Kidney?? No reports in
dogs, but recognized syndrome in humans
Medullary Sponge Kidney
Usually non-progressive, asymptomatic Often found incidentally during renal imaging Clinical signs, if present, include hematuria, UTI,
or renal calculi May have mild concentration defect or mild
proteinuria High risk of struvite or oxalate calculi May be associated with congenital
hemihypertrophy and Wilms’ tumor, but not always
Medullary Sponge Kidney
Laboratory tests: urinalysis, calcium excretion (tend to be hypercalciuric), urine culture (may have UTI—urine stasis)
Imaging: excretory urography (radial, linear striations in papillae, or cystic, ectatic collecting ducts)
Ultrasound or CT useful, but probably unnecessary, as this is not a progressive dz
Treatment of Humans with MSK
If hypercalciuric, thiazide diuretics Manage any renal calculi Treat UTIs with antibiotics Decreased Na/Increased K intake
References
Ginalski J, Portmann L, Jaeger P. Does medullary sponge kidney cause nephrolithiasis? American Journal of Roentgenology 1990; 155:299-302.
Rommel D, Pirson Y. Medullary sponge kidney—part of a congenital syndrome. Nephrology Dialysis Transplantation 2001; 16:634-636.
Trachtman H. Medullary sponge kidney. www.emedicine.com/ped/topic1394.htm 2007.