CASE 9995 Published on 08.05.2012
0

Impressive urinoma from intermediate calyx tear

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Aringhieri G, Lorenzi S, Scalise P, Angelini G, Pancrazi F, Accogli S, Ginanni B, Lauretti D, Caproni G, Bartolozzi C

Department of Diagnostic and Interventional Radiology,
University Hospital of Pisa, Italy
Connected authors
Patient

43 years, male

Categories
Area of Interest Abdomen, Kidney, Urinary Tract / Bladder ; Imaging Technique CT, Image manipulation / Reconstruction
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Clinical History
A 43-year-old drug addicted male patient, in Methadone Maintenance Treatment (MMT) and with clinical history of viral hepatitis (HCV+, HBV+) presented with haematuria, pyuria and septic fever. An ultrasound examination, made in another center, showed a perirenal fluid hypoechoic collection. The patient came to our department for a Computer Tomography (CT) evaluation.
Imaging Findings
Abdominal CT showed a marked subcapsular fluid collection (APxLLxCC:11x14x22cm) in left perirenal space, displacing forwards the omolateral renal parenchyma [Fig. 1].
The formation, with internal septations and peripherical wall-enhancement, was medially in contact with omolateral psoas muscle, aorta [Fig.1d-f] and major renal artery.
An ultra-delayed phase acquisition (30min) showed abundant iodinate urine shedding in the context of the described collection [Fig. 2], demonstrating a tear of the intermediate calyx in its papillary region, feeding the urinoma [Fig. 3].
The ureter appeared slightly compressed, but still patent [Fig. 3].
A percutaneous pig-tail drainage was performed and follow-up CT showed the collection almost completely drained in retroperitoneal medial region, while the posterior component still remained in place.
A month later, CT showed air inside the collection previously described, suggesting a retroperitoneal abscess [Fig. 4a, c].
Air content was also detected inside the abdominal wall, where the drainage was placed, associated with non-homogeneous thickening of the soft tissues (cutaneous fistula) [Fig. 4b, d].
Discussion
Urinoma is defined as a fluid collection surrounded by a fibrous capsule, resulting from chronic tissue irritation by urine[1,2,3].
A maintained renal function is an essential requirement for the development of urinomas, as well as the rupture of collecting system[2] and fibrous reactive capsule.
Causes of urinary leaks and urinomas are various, depending on the site of the rupture.
Most frequent causes are penetrating trauma, iatrogenic injury and transmitted back pressure caused by a downstream obstruction (ureteral stone, abdominal/pelvic masses, retroperitoneal fibrosis)[1].
Urinary leak or urinomas might also result during systemic drug assumption, causing renal ischemic injury, such as papillary necrosis, which might lead to the rupture of the junction between calyxes and papillas, creating a way out for the urine.
Common clinical manifestations include malaise, vague abdominal pain, weight loss and the presence of a palpable mass; haematuria, pyuria, nausea, vomiting, paralytic ileus and altered levels of serum creatinine and electrolytes might be associated.
Nonetheless, urine leaks might be occult and asymptomatic[1].
Imaging plays a crucial role in diagnosis and follow-up, identifying the leaks, their causes and extent.
US-examination represents the first level imaging technique which usually detects:
-fluid effusion or collections, often in perirenal space, as multiloculated, thick-walled and hypoechoic masses;
-indirect signs of obstruction, like ureteral dilatation.
The origin of the urine leak might be identified with Colour/Power-DopplerUS, which show the periodic jet-flow supplying the collection[1].
CT is the gold-standard technique in the diagnosis of urinary tears.
Contrast-enhanced delayed-phase images are the most useful acquisitions to detect leaks, since they allow demonstrating an increase in density of the urinoma over time due to the iodinate contrast,[4] or the absence of opacification in the distal urinary tract[1]. Three-dimensional reformatted images can define the exact site of the tear and the precise size of the urinoma[4]. Moreover, CT might evaluate the presence of urinary ascites, which frequently occurs in ureteral leaks, the superinfection of the fluid collection, due to urinary stasis, and any possible complications after treatment or during follow-up[5,6].
In comparison to CT, intravenous pyelography has low sensitivity, with over 30% of false negative results[7].
Also retrograde/anterograde pyelography might be useful especially in ureteral leaks.
Retrograde cistography or urethrography are the diagnostic tests of choice to detect respectively urinary bladder[8] or urethral leaks.
Therapeutic options for urinomas depend on their size: small formation might reabsorb spontaneously, while bigger ones must be drained through CT/US-guided catheter or percutaneous nephrostomy, especially in case of septic complications.
Urinary bladder intraperitoneal leaks must be evaluated by open-surgical exploration.
Differential Diagnosis List
Urinoma of the left perirenal space due to drug-induced (MMT) renal papillary necrosis.
Haematoma
Abscess
Renal cyst
Benign neoplasm
Malignant neoplasm
Metastases
Teratoma
Lynphocele
Lymphangiomatosis
Final Diagnosis
Urinoma of the left perirenal space due to drug-induced (MMT) renal papillary necrosis.
Case information
URL: https://www.eurorad.org/case/9995
DOI: 10.1594/EURORAD/CASE.9995
ISSN: 1563-4086
Figure 1

First CT examination - Baseline and venous-phase acquisition

First CT examination - Baseline and venous-phase acquisition
Baseline abdominal CT showing marked subcapsular renal fluid collection in the left perirenal space, displacing forwards the omolateral renal parenchyma; on its medial side in contact with omolateral psoas muscle and left wall of aorta.
First CT examination - Baseline and venous-phase acquisition
Baseline abdominal CT showing marked subcapsular renal fluid collection in the left perirenal space, displacing forwards the omolateral renal parenchyma; on its medial side in contact with omolateral psoas muscle and left wall of aorta.
First CT examination - Baseline and venous-phase acquisition
Baseline abdominal CT showing marked subcapsular renal fluid collection in the left perirenal space, displacing forwards the omolateral renal parenchyma; on its medial side in contact with omolateral psoas muscle and left wall of aorta.
First CT examination - Baseline and venous-phase acquisition
Venous-phase abdominal CT evaluation showing marked subcapsular renal fluid collection in the left perirenal space, within septations and with peripherical wall-enhancement.
First CT examination - Baseline and venous-phase acquisition
Venous-phase abdominal CT evaluation showing marked subcapsular renal fluid collection in the left perirenal space, within septations and with peripherical wall-enhancement.
First CT examination - Baseline and venous-phase acquisition
Venous-phase abdominal CT evaluation showing marked subcapsular renal fluid collection in the left perirenal space, within septations and with peripherical wall-enhancement.
Figure 2

First CT examination - Ultra-delayed phase acquisition

First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
First CT examination - Ultra-delayed phase acquisition
Ultra-delayed phase CT evaluation showing abundant iodinate urine shedding in the context of the decribed collection, demonstrating a calyx tear feeding the urinoma.
Figure 3

First CT examination - Post processing images

First CT examination - Post processing images
Ultra-delayed phase CT MPR-image showing iodinate urine shedding in the context of the collection, demonstrating a tear of the intermediate calyx in its papillary region, feeding the urinoma. The ureter appeares compressed, but still patent.
First CT examination - Post processing images
Ultra-delayed phase CT MPR-zoomed-image showing iodinate urine shedding in the context of the collection, demonstrating a tear of the intermediate calyx in its papillary region, feeding the urinoma. The ureter appeares compressed, but still patent.
First CT examination - Post processing images
Ultra-delayed phase CT MPR-zoomed-image showing iodinate urine shedding in the context of the collection, demonstrating a tear of the intermediate calyx in its papillary region, feeding the urinoma. The ureter appeares compressed, but still patent.
Figure 4

CT examination, one month later - Baseline and venous-phase acquisition

CT examination, one month later - Baseline and venous-phase acquisition
Baseline abdominal CT showing abundant air in place of the collection previously described, suggesting a retroperitoneal abscess.
CT examination, one month later - Baseline and venous-phase acquisition
Baseline abdominal CT showing the retroperitoneal abscess. Air content is also detectable inside the abdominal wall, where the drainage was placed, associated with non-homogeneous thickening of the soft tissues, suggesting a cutaneous fistula (red circle).
CT examination, one month later - Baseline and venous-phase acquisition
Venous-phase abdominal CT evaluation showing abundant air in place of the fluid collection previously described, with typical air-fluid levels, suggesting of retroperitoneal perirenal abscess.
CT examination, one month later - Baseline and venous-phase acquisition
Venous-phase abdominal CT showing typical air-fluid levels of the retroperitoneal perirenal abscess and air content inside the postero-lateral abdominal wall, associated with non-homogeneous thickening of the soft tissues, suggesting a cutaneous fistula.