Urothelial Cancer of the Renal Pelvicaliceal System: Unusual Imaging Manifestations

Abstract

Unusual imaging features of urothelial cancer of the renal pelvicaliceal system can be challenging for any radiologist. These manifestations include noncalcified and calcified focal infiltrative parenchymal masses, incidentally detected tumors in a hydronephrotic kidney due to ureteropelvic junction obstruction, transpelvic infiltrating solid masses extending through the retroperitoneum, and tumors primarily invading the perirenal fat. Less common manifestations include massive papillary frond-like projections within a large hydronephrotic sac, large multiloculated cystic masses with thick and irregular septa, tumors invading the renal vein, and paraaortic lymph node metastases as the only sign of an undetectable primary tumor of the renal collecting system. Radiologists should be aware that an eccentric, focal, infiltrative pelvicaliceal carcinoma that causes distortion of the renal contour may simulate renal cell carcinoma; when calcified, such a pelvicaliceal carcinoma may simulate chronic inflammatory renal disease. The radiologist should also be aware of the importance of a meticulous sonographic evaluation of a hydronephrotic kidney, particularly in older patients, to avoid missing a urothelial cancer. When a nonfunctioning and enlarged kidney is present, radiologists should always consider infiltrative hydronephrotic urothelial carcinoma as a diagnostic possibility. Familiarity with unusual imaging features of urothelial cancer of the renal pelvicaliceal system may facilitate making the correct diagnosis, thus enabling adequate therapeutic management.

Centrally Infiltrating Renal Masses on CT: Differentiating Intrarenal Transitional Cell Carcinoma From Centrally Located Renal Cell Carcinoma

“…Although our study broadly supports the theory that this feature is characteristic of intrarenal TCC, a centrally located RCC can show similar features, and we suggest that accurately locating the tumor center is more important than merely identifying a connection between the tumor and collecting system. Similarly, renal contour is usually maintained in intrarenal TCC and serves as a useful supportive feature, but centrally located RCCs can also present with a preserved renal shape and eccentric intrarenal TCC can occasionally distort the renal outline [22]. Differentiation in these cases will be aided by searching for the other described features.…”

“…Renal vein invasion is a feature much more suggestive of centrally located RCC, although rarely TCC can invade the renal vein or even the inferior vena cava [22,24,25]. Any calcified renal lesion regardless of the pattern of calcification is more likely to be a centrally located RCC, but calcification can also occasionally occur with TCC [24].…”

Contrast enhanced ultrasound of renal masses. A reappraisal of EFSUMB recommendations and possible emerging applications.

“…Primary tumours of the renal pelvis and ureter account for up to 10-15% of all urinary tract tumours, more than 90% of which are urothelial carcinomas [36]. The role of US in diagnosing the type of intracaliceal /intraurethral masses is limited.…”

Renal Pelvic Urothelial Carcinoma With Vena Caval Thrombus Mimicking Renal Cell Carcinoma

“…Invasion of the renal vein in the renal hilum or the IVC is considered to be a rare event and an uncommon late finding in urothelial carcinoma of the pelvocaliceal system [5]. Vena caval involvement by intraluminal extension of the tumor mass has been reported to occur in 4% to 10% of patients with renal neoplasm [6]. In a previous report on upper tract urothelial carcinoma with vena caval thrombi, of 18 cases, 6 cases underwent nephroureterectomy with vena caval reconstruction; 4 had nephroureterectomy with thrombectomy; 2 had nephrectomy and thrombectomy with chemotherapy; 3 had nephroureterectomy and thrombectomy; 1 had nephroureterectomy, thrombectomy, and radiation; 1 had nephroureterectomy, thrombectomy, and chemotherapy; and 1 underwent biopsy only [7].…”