Editorial Comment on: A. Smereczyński, T. Szopiński, T. Gołąbek, O. Ostasz and S. Bojko Sonography of tumors and tumor-like lesions that mimic carcinoma of the urinary bladder.

We read with great interest the article written by Smereczyński et al.(, who performed an exhaustive evaluation of the bladder pseudotumors found at the ultrasound examination, that raise problems of differential diagnosis with real bladder tumors.

The ultrasound is the most common imaging method for the evaluation of patients presenting for hematuria. The advantages of this investigation are that it is widely accessible, it allows an accurate exploration of the urinary tract, it is not invasive and does not involve exposure to contrast substance or X-rays (it can be used for pregnant patients or patients with renal impairment). However, this investigation is limited by the subjectivity and experience of the examiner.

The bladder ultrasound exploration can be achieved by transabdominal or endocavitary (transrectal or transvaginal) access and allows the correct assessment of the pathology of this organ, although a negative result does not exclude with certainty the presence of bladder tumors(.

The detection rate of bladder tumors is influenced by their location and size, meaning that the tumors located in the dome or the trigone of the bladder and smaller than 0.5 cm are more difficult to objectify by ultrasound. For other locations or large tumors, the diagnostic accuracy of the ultrasound is 95%. Other situations that pose a diagnostic challenge are the flat form tumors, the presence of intravesical blood clots or calcified bladder tumors. Also, the examination is difficult in patients with rigid abdominal wall or morbid obesity(.

In addition to Smereczyński article, I would like to mention other ultrasound techniques that have been developed in order to increase the accuracy of the examination of the urinary bladder: the contrast-enhanced ultrasound, tri-dimensional ultrasound (3D ultrasound) or even virtual cystoscopy. These complementary methods allow the differentiation of real bladder tumors from the pseudotumors and the differentiation between superficial and infiltrative bladder tumors.

The contrast-enhanced ultrasound is superior to conventional methods when differentiating superficial from infiltrative forms, with an accuracy of 88.4% in detecting bladder tumors before TUR-V, in comparison to 72.1% for the standard ultrasound. The highest sensitivity (94.7%) is achieved for bladder tumors larger than 5 mm, but decreases to 20% for tumors smaller than 5 mm. Also, contrast-enhanced ultrasound allows the differentiation from the bladder pseudotumors like chronic inflammatory lesions or papillary hyperplasia(.

The ultrasound with 3D reconstruction is based on the ability to process the images obtained from the analysis of the bladder wall and provide real-time insight into multiple planes of the primary tumor. The advantage of this method is that it allows the evaluation of the perivesical extension of the tumors, with a detection rate of 100% for T3b tumors(. The combination of these two techniques, contrast-enhanced and 3D ultrasound, is considered a future prospect in differentiating superficial from infiltrative bladder tumors, and most important, for assessing the response to bladder sparing therapy.

The 3D reconstruction based on the images provided by ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) allows an indirect visualization of the bladder mucosa and the simulation of an endoscopic assessment. Virtual cystoscopy performed by acquiring images from CT, MRI or ultrasound has a sensitivity for the evaluation of bladder tumors of 93.9%, 90.8% and 77.9%, and a specificity of 98.1%, 94.8% and 96.2% respectively(.

In conclusion, the rapid diagnosis and staging of bladder tumors has an increasing importance considering the progressive potential that this oncological pathology holds. The correct evaluation of the bladder pseudotumors using ultrasound helps conducting the differential diagnosis. Also, the use of new imaging techniques (contrast-enhanced or 3D ultrasound) completes the panel of information needed in order to formulate a correct and complete diagnosis of the urinary bladder pathology.