Urinary System

Ureter - Dilation

Narrative
Comment:
Dilation of the ureter (synonym: hydroureter) is most commonly associated with cases of obstruction. Often it can be seen grossly with dilation of the urinary bladder and renal pelvis. It can be either unilateral or bilateral (Figure 1). In rats, congenital cases are more prevalent on the right side. A strain of mouse (NON/Shi) and a strain of rat (SD/cShi) have been developed that have spontaneous hydroureter and hydronephrosis and can be induced to develop proliferative lesions of the renal pelvic urothelium.
Recommendations:
Dilation of the ureter should be diagnosed and assigned a severity grade. If ureter dilation is treatment related, the study pathologist should describe whether the lesion is unilateral or bilateral.
References:

Anver M, Haines D, Swing D, Ward J. 2001. Transitional cell proliferative lesions of the ureter with hydronephrosis in B6D2F1/Cr mice. Vet Pathol 38:5.

Bendele M. 1998. Urologic syndrome, mouse. In: Monographs on Pathology of Laboratory Animals: Urinary System, 2nd ed (Jones TC, Hard GC, Mohr U, eds). Springer, Berlin, 456-462.

Abstract: http://www.ilsi.org/publications/urinarysystem.pdf

Maronpot RR. 1998. Spontaneous hydronephrosis, rat. In: Monographs on Pathology of Laboratory Animals: Urinary System, 2nd ed (Jones TC, Hard GC, Mohr U, eds). Springer, Berlin, 306-309.

Abstract: http://www.ilsi.org/publications/urinarysystem.pdf

Murai T, Mori S, Hosono M, Takeuchi Y, Ohara T, Makino S, Takeda R, Hayashi Y, Fukushima S. 1991. Renal pelvic carcinoma which shows metastatic potential to distant organs induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in NON/Shi mice. Jpn J Cancer Res 82:1371-1377.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/1778760

Murai T, Mori S, Machino S, Hosono M, Takeuchi Y, Ohara T, Makino S, Takeda R, Hayashi Y, Iwata H, Yamamoto S, Ito H, Fukushima S. 1993 Induction of renal pelvic carcinoma by phenacetin in hydronephrosis-bearing rats of the SD/cShi strain. Cancer Res 53:4218-4223.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/8364917
  • Image of dilation in the ureter from a male mouse

    Greatly dilated ureter (arrow) of probable familial origin from a male mouse.

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<p>Greatly dilated ureter (arrow) of probable familial origin from a male mouse.</p>

Greatly dilated ureter (arrow) of probable familial origin from a male mouse.

Authors

John Curtis Seely, DVM, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Abraham Nyska,  DVM, Diplomate ECVP, Fellow IATP
Expert in Toxicologic Pathology
Visiting Full Professor of Pathology
Sackler School of Medicine, Tel Aviv University
Timrat Israel

Reviewers

Samuel M Cohen, PHD, MD
Professor
Havlik-Wall Professor of Oncology
Director of Pathology Residency Program
Nebraska Medical Center
Omaha, NE

David E. Malarkey DVM, PhD, DACVP, FIATP
Head, National Toxicology Program Pathology Group
Cellular and Molecular Pathology Branch
Division of the National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC