INTRODUCTION
Partial spontaneous rupture of the upper urinary tract is rare and usually associated with nephrolithiasis. Other reported causes, apart from instrumentation and trauma, involve obstructive ureteral tumor in the pelvic cavity, retroperitoneal fibrosis, fluid overload, and pregnancy. We report a case of spontaneous rupture of renal pelvis secondary to ureteral obstruction caused by urothelial tumor, clinically suspected and evaluated by CT scans and MRIs, discussing the relevant findings for diagnosis.
CASE REPORT
Male patient, 55 years, with a clinical picture of macroscopic hematuria and insidious lower back pain similar to cramps for about six months, which became stronger in recent months. The patient reports a fever, not measured. Denies trauma, previous surgery, history of urolithiasis, other complaints, and past illnesses. Former smoker (22 packs/year, having quit smoking for eight years). On physical examination, the patient showed good general health, being thin (body mass index of 17.2 Kg/m2), pallid (1+/4), hypohydrated (2+/4), acyanotic, anicteric, eupneic and afebrile. Abdomen with bowel sounds present and preserved, slightly painful on palpation in the left flank and iliac fossa. Painful lumbar fist percussion on the left.
Based on the clinical picture, we requested a contrasted multi-slice computed tomography (Figures 1A and 1B) and subsequent complementation with MR urography - Uro-MRI (Figures 2A, 2B, 2C and 2D). Vascularized tumoral thickening of the proximal left ureter evident, causing ureteral obstruction and moderate pyelocaliceal upstream dilation. Associated rupture of the renal pelvis with contrast extravasation and formation of posterior perirenal urinoma is also observed, displacing the kidney anterolaterally.
Computed tomography, contrast-enhanced axial sections; excretory phase shows irregular parietal thickening of the left ureteropelvic junction, causing ureteral obstruction (black arrow) and moderate upstream pyelocaliceal dilatation (dashed arrow). Rupture of the renal pelvis with contrast extravasation and formation of posterior perirenal urinoma is also observed (white arrow).
MRI with T2-weighted images, coronal (2A) and axial (2B), three-dimensional MR urography (2C) and post-contrast T1 image (2D) revealing vascularized tumoral thickening of the proximal left ureter (black arrow), causing ureteral obstruction and moderate pyelocaliceal upstream dilation (dashed arrow). Associated rupture of the renal pelvis with contrast extravasation and formation of posterior perirenal urinoma also observed (white arrow), displacing the kidney anterolaterally.
Imaging diagnosis (with subsequent histopathological confirmation) led to the conclusion that it was a case of spontaneous rupture of renal pelvis and formation of urinoma secondary to ureteral obstruction due to urothelial tumor.
DISCUSSION
In the case described, the spontaneous rupture of renal pelvis was caused by urothelial
tumor. The rupture diagnosis can be clinically suspected and confirmed by imaging. The
clinical picture includes macro or microscopic hematuria (75%), back pain (18%), dysuria
(6%) and less frequently palpable mass, decreased appetite, weight loss, and may
sometimes be asymptomatic.11. Tripathi S, Ahmad A, Mathew VV. Spontaneous partial rupture of the
upper renal tract. Case Report. Brunei Int Med J. 2011;7(4):215-219.
2. Ashebu SD, Elshebiny YH, Dahniya MH. Spontaneous rupture of the renal
pelvis. Australas Radiol. 2000;44:125-7.
3. Kaplan M, Aktoz T, Atakan IH. A rare cause of acute flank pain:
spontaneous rupture of the renal pelvis. Turkish Journal of Urology
2009;35(3):256-259.-44. Inahara M, Kojima S, Takei K, Naito H, Kito H, Yamazaki K, et al. Two
cases of spontaneous rupture of upper urinary tract caused by the primary ureteral or
renal pelvic tumor: a case report. Acta Urologica Japonica.
2009;55(1):31-34.
Urothelial tumors can affect any part of the urinary tract is relatively rare in the
upper urinary tract (approximately 1% of all urothelial tumors), most frequently
affecting patients in the sixth and seventh decades of life. The histological subtypes
include transitional cell carcinoma (TCC) (90%), squamous cell carcinoma (9%), mucinous
adenocarcinoma (less than 1%), sarcomas, undifferentiated tumors and benign tumors
(mesodermal inverted papilloma, and fibroepithelial polyp). Risk factors involve
smoking, prolonged exposure to dyes such as aniline, petrochemical agents and tar,
analgesic abuse (especially phenacetin), Balkan nephropathy, as well as factors that
promote urinary stasis, as horseshoe kidneys. The use of cyclophosphamide, in turn,
increases the risk of high-grade urothelial tumors. Chronic infection and calculi may
also be associated with squamous cell carcinoma and mucinous adenocarcinoma.
Schistosomiasis can be associated with the squamous cell carcinoma, and also seems to be
associated with a greater degree of epigenetic changes in the epithelium of the
genitourinary tract.44. Inahara M, Kojima S, Takei K, Naito H, Kito H, Yamazaki K, et al. Two
cases of spontaneous rupture of upper urinary tract caused by the primary ureteral or
renal pelvic tumor: a case report. Acta Urologica Japonica.
2009;55(1):31-34.
5. Prando A. Tumores uroteliais. In: Muller CIS, D'Ippolito Giuseppe,
Rocha AJ, series editors. Prando A, Baroni RH, associated editors. Urinário (Colégio
Brasileiro de Radiology and Diagnostic Imaging; 5). Rio de Janeiro: Elsevier; 2013.
p. 321-358.-66. Gutiérrez MI, Siraj AK, Khaled H, Koon N, El-Rifai W, Bhatia K. CpG
island methylation in Schistosoma- and non-Schistosoma-associated bladder cancer.
Modern Pathology. (2004) 17,1268-1274.
There is a clear need in patients with upper urinary tract tumors for imaging
investigation of the entire urinary tract, due to possible synchronous bladder cancer in
2-4% of patients. Furthermore, the need for follow-up is well established, as 40-50% of
patients with TCC will develop metachronous tumours involving the lower urinary
tract.33. Kaplan M, Aktoz T, Atakan IH. A rare cause of acute flank pain:
spontaneous rupture of the renal pelvis. Turkish Journal of Urology
2009;35(3):256-259.
4. Inahara M, Kojima S, Takei K, Naito H, Kito H, Yamazaki K, et al. Two
cases of spontaneous rupture of upper urinary tract caused by the primary ureteral or
renal pelvic tumor: a case report. Acta Urologica Japonica.
2009;55(1):31-34.-55. Prando A. Tumores uroteliais. In: Muller CIS, D'Ippolito Giuseppe,
Rocha AJ, series editors. Prando A, Baroni RH, associated editors. Urinário (Colégio
Brasileiro de Radiology and Diagnostic Imaging; 5). Rio de Janeiro: Elsevier; 2013.
p. 321-358.
Urotomography (Uro-CT) performed with equipment with multiple rows of detectors (MDCT)
is being increasingly used for evaluation of synchronous and metachronous tumors in the
upper urinary tract and primary evaluation of hematuria. Imaging studies are also used
to differentiate tumors and benign urothelial changes which might not require additional
invasive assessment such as ureteroscopy and retrograde pyelography.77. Silverman SG, Leyendecker JR, Amis ES. What is the current role of CT
urography and MR urography in the evaluation of the urinary tract? Radiology
2009;250:309-323.
8. Dillman JR, Caoili EM, Cohan RH, Ellis JH, Francis IR, Schipper MJ.
Detection of upper tract urothelial neoplasms: sensitivity of axial, coronal
reformatted, and curved-planar reformatted image-types utilizing 16-row
multi-detector CT urography. Abdom Imaging 2008;33:707-716.-99. Sadow CA, Wheeler SC, Kim J, Ohno-Machado L, Silverman SG. Positive
Predictive Value of CT Urography in the Evaluation of Upper Tract Urothelial Cancer.
AJR 2010;195:337-343. The differential diagnosis of tumors in the upper urinary tract includes
nephrolithiasis, blood clot, infection, tuberculosis, ectopic papilla, endometriosis and
malakoplakia. Factors that help to reach a correct diagnosis include knowledge of the
location, lesion density and pattern of impregnation, pericalicinal/periureteral
opacification associated or not, and multiplicity of lesions. In the unenhanced phase of
Uro-CT, TCCs are discreetly hyperdense compared to urine (15-30HU), unlike clots and
stones (with respective densities at 40-80 HU and above 200HU). Since most of them are
hypovascularized, they are discreetly impregnated by contrast (increase of 40-70HU), and
to a lesser intensity than normal renal parenchyma, appearing in the excretory phase of
the examination as fixed filling defects.55. Prando A. Tumores uroteliais. In: Muller CIS, D'Ippolito Giuseppe,
Rocha AJ, series editors. Prando A, Baroni RH, associated editors. Urinário (Colégio
Brasileiro de Radiology and Diagnostic Imaging; 5). Rio de Janeiro: Elsevier; 2013.
p. 321-358. In
addition to technological improvements in MDCT, refinements in the tests' radiological
orientation have probably contributed to increase the capacity to detect urothelial
abnormalities. Different techniques have been used, such as abdominal compression,
administration of intravenous saline solution, diuretics or both, "log-rolling" (asking
patients to roll 360º) prior to excretory phase to maximize opacification and distention
of the urinary tract.
On MRI, TCCs can appear hypointense or isointense compared to the renal parenchyma on T1- and T2-weighted sequences, making it necessary to use paramagnetic contrast agents in non-dilated urinary tract, being the TCCs less contrasted than the renal parenchyma. In patients with impaired renal function, static MR urography can help detect tumors of the upper urinary tract, especially in obstructed kidneys, since TCCs are usually hypointense compared to urine on T2-weighted images, which facilitates their detection when associated to hydronephrosis. The use of diffusion-weighted imaging (DWI) sequences associated with conventional T1- and T2-weighted sequences increases the accuracy and sensitivity of Uro-MRI.1010. Yoshida S, Masuda H, Ishii C, Tanaka H, Fujii Y, Kawakami S, et al. Usefulness of Diffusion-Weighted MRI in Diagnosis of Upper Urinary Tract Cancer. AJR 2011;196:110-116.,1111. Padhani AR, Liu G, Koh DM, Chenevert TL, Thoeny HC, Takanara T, et al. Diffusion-weigheted magnetic resonance imaging as a cancer biomarker: consensus and recommendations. Neoplasia 2009;11:102-125.
CONCLUSION
Although rare, spontaneous rupture of renal pelvis secondary to ureteral obstruction caused by urothelial tumor may be suspected clinically, and the detailed radiological analysis of tomographic images and MRI-guided sequences, including Uro-MRI, is of great importance for both diagnosis and follow-up of these patients.
REFERENCES
-
1Tripathi S, Ahmad A, Mathew VV. Spontaneous partial rupture of the upper renal tract. Case Report. Brunei Int Med J. 2011;7(4):215-219.
-
2Ashebu SD, Elshebiny YH, Dahniya MH. Spontaneous rupture of the renal pelvis. Australas Radiol. 2000;44:125-7.
-
3Kaplan M, Aktoz T, Atakan IH. A rare cause of acute flank pain: spontaneous rupture of the renal pelvis. Turkish Journal of Urology 2009;35(3):256-259.
-
4Inahara M, Kojima S, Takei K, Naito H, Kito H, Yamazaki K, et al. Two cases of spontaneous rupture of upper urinary tract caused by the primary ureteral or renal pelvic tumor: a case report. Acta Urologica Japonica. 2009;55(1):31-34.
-
5Prando A. Tumores uroteliais. In: Muller CIS, D'Ippolito Giuseppe, Rocha AJ, series editors. Prando A, Baroni RH, associated editors. Urinário (Colégio Brasileiro de Radiology and Diagnostic Imaging; 5). Rio de Janeiro: Elsevier; 2013. p. 321-358.
-
6Gutiérrez MI, Siraj AK, Khaled H, Koon N, El-Rifai W, Bhatia K. CpG island methylation in Schistosoma- and non-Schistosoma-associated bladder cancer. Modern Pathology. (2004) 17,1268-1274.
-
7Silverman SG, Leyendecker JR, Amis ES. What is the current role of CT urography and MR urography in the evaluation of the urinary tract? Radiology 2009;250:309-323.
-
8Dillman JR, Caoili EM, Cohan RH, Ellis JH, Francis IR, Schipper MJ. Detection of upper tract urothelial neoplasms: sensitivity of axial, coronal reformatted, and curved-planar reformatted image-types utilizing 16-row multi-detector CT urography. Abdom Imaging 2008;33:707-716.
-
9Sadow CA, Wheeler SC, Kim J, Ohno-Machado L, Silverman SG. Positive Predictive Value of CT Urography in the Evaluation of Upper Tract Urothelial Cancer. AJR 2010;195:337-343.
-
10Yoshida S, Masuda H, Ishii C, Tanaka H, Fujii Y, Kawakami S, et al. Usefulness of Diffusion-Weighted MRI in Diagnosis of Upper Urinary Tract Cancer. AJR 2011;196:110-116.
-
11Padhani AR, Liu G, Koh DM, Chenevert TL, Thoeny HC, Takanara T, et al. Diffusion-weigheted magnetic resonance imaging as a cancer biomarker: consensus and recommendations. Neoplasia 2009;11:102-125.
-
Study conducted at the Department of Radiology, Faculty of Medical Sciences - State University of Campinas (FCM-Unicamp), Campinas, SP, Brazil.
Publication Dates
-
Publication in this collection
Sep-Oct 2014
History
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Received
06 Oct 2013 -
Accepted
20 Feb 2014