Clinical History
The patient presented with painless gross intermittent hematuria.
Imaging Findings
The patient had history of smoking for several years and presented with signs of painless gross intermittent hematuria. He was initially investigated with renal ultrasound and IV urography. Both
examinations showed right hydronephrosis and dilatation of the proximal right ureter but were unable to reveal the cause of obstruction. CT was subsequently performed with additional injection of IV
contrast-medium (CM). Right hydronephrosis with dilatation of the proximal right ureter was confirmed. Additionally, a focal distension of the right ureter was identified at the level of its mid
third with no evidence of stranding of the periureteral fat. An intraluminal soft-density lesion was revealed on the delayed post-contrast images with the patient prone in position. It occupied the
ureteral lumen and showed board attachment surface to the ureteral wall. There was no evidence of lymphadenopathy in the abdomen.
Discussion
Ureteral tumors are rare lesions accounting for only 1% of all upper geniturinary tract neoplasms. Review studies report that almost 80% of the ureteral neoplasms are malignant. The radiological
features of differential diagnosis between malignant and benign ureteral lesions may be ambigious, so that radiologists should be aware of their clinical presentation and the predisposing factors.
Non-contrast Computed Tomography (NCCT) has the ability to diagnose a wide range of entities that result in renal colic and ureteral obstruction. Under the suspicion of an underlying ureteral tumor
in a patient with ureteral obstruction, NCCT can exclude calcular causes of obstruction (apart from the indinavir urolithiasis, all stones are visible on NCCT). Additionally it can reveal the tumor
itself and its possible association with a stone causing obstruction. Transitional cell carcinoma (TCC) appears on NCCT as an intraluminal soft tissue mass and/ or as an eccentric or circumferential
thickening of the ureteral wall. In cases where the renal function permits the use of contrast medium, Contrast Enhanced Computed Tomography (CECT) appears to be complementary to NCCT. CECT can
overcome potential pitfalls in the interpretation of NCCT such as phleboliths in the anatomic course of the ureter mimicking ureteral stones or a gonadal vein that can be confused with a dilated
ureter. Moreover CECT gives the radiologist information about the lumen of the ureter and it helps to differentiate between a malignant and a benign tumor: In CECT, fibroepithelial polyps appear as
solid intraluminal, longitudinal masses attached to the ureteral wall with presence of a continuous rim of contrast medium surrounding the central part of the solid mass. This kind of CT appearance
excludes stones, blood clots, fungus balls as well as polypoid transitional cell carcinomas provided that the surrounding ureteral wall is thin. In CECT, TCCs may appear as intraluminal filling
defects with thickening of the wall that may be concentric, eccentric and/ or irregular. Since CT has the ability to assess the periureteral extension of these tumors, it enables staging. Stage I
lesions limited to the lamina propria and Stage II lesions infiltrating the muscular layer can not be differentiated with current CT technology; nevertheless, there is no therapeutic differentiation
for these two stages. Soft tissue stranding in the periureteral fat in the vicinity of the tumor is regarded as evidence of Stage III. Enlarged retroperitoneal lymph nodes and distant metastases
render the patient Stage IV.
Differential Diagnosis List
Transitional cell Ca of the right ureter (Stage II)
Final Diagnosis
Transitional cell Ca of the right ureter (Stage II)
