Urothelial implantation of Wilms' tumors

Ureteral extension in Wilms' tumor: a report from the National Wilms' Tumor Study Group (NWTSG)

BACKGROUND

Extension of Wilms' tumor into the ureter is a rare event. We reviewed the National Wilms' Tumor Study Group (NWTSG) database to define the clinical presentation, associated pathologic features, and clinical outcome of these patients.

METHODS

Records of children identified to have ureteral extension of Wilms' tumor enrolled in NWTS-3, 4, and 5 were reviewed. Presenting symptoms, diagnostic studies, histopathologic findings, operation performed, and outcome were recorded. The NWTS-5 surgical data were prospectively collected as part of the quality assurance program.

RESULTS

Forty-five children were identified with ureteral extension. For NWTS-5, the incidence of ureteral extension was 2%. Clinical presentations were gross hematuria in 22 patients, 2 had passage of tissue per urethra, and 1 child had a urethral mass. The remainder had nonspecific presentations. Ureteral extension was seen on preoperative imaging in 14 patients, intraoperatively in 22, and on pathologic examination in 9 patients. Hydronephrosis was noted in 12 patients, and there was nonfunction of the kidney in another 8. Laterality of the tumor was right side in 26 and left in 19. Cystoscopy was performed in 12 children. Findings included tumor seen at the ureteral orifice in 6 patients and bleeding from the orifice in one child. All patients had radical nephrectomy including partial ureterectomy. The ureteral margin was positive in 3 patients, including 2 of the 7 with separate removal of the ureteral extension. The number of patients in each clinical stage was as follows: stage I, 10; stage II, 18; stage III, 14; and stage IV, 3. The tumor extended into the proximal ureter in 23 patients, distal ureter in 13, 7 had extension into the bladder, and 1 had urethral involvement. The level of ureteral extension was not clearly noted in the 45th child. The median follow-up was 96 months. Overall, 41 of 45 patients were alive at last contact. There were 3 deaths because of tumor in patients with unfavorable histologic tumors, and 1 because of treatment toxicity in a child with favorable histologic findings.

CONCLUSIONS

Ureteral extension occurs in approximately 2% of patients with Wilms' tumor. The diagnosis should be suspected in patients with gross hematuria, hydronephrosis, or nonfunctioning kidney. Cystoscopy with retrograde ureterogram may aid in preoperative diagnosis in these patients. Preoperative diagnosis is important because complete resection of the involved portion of ureter at the time of nephrectomy can avoid residual disease and the need for second surgery or radiation therapy.

Wilms' tumor: transureteral intravesical extension and presentation as urinary retention

The authors report an unusual case of Wilms' tumor. The tumor grew transureterally into the urinary bladder, became dislodged, and presented as recurrent urinary infection with retention of urine after the child underwent nephroureterectomy. Such a presentation has not been reported earlier.

Wilms tumor extending into the dilated renal pelvis as a mold

A case of Wilms tumor associated with hydronephrosis is reported. The tumor extended into the dilated renal pelvis but there was no invasion in the mucosa of the ureter or renal pelvis.

Polypoid renal pelvic lesions in children

A case is presented of gross hematuria and a large polypoid renal pelvic mass in a 15-month-old boy. Operation revealed a Wilms tumor with limited parenchymal involvement and rupture into the collecting system. This rare presentation of nephroblastoma and its differentiation from other rare benign and malignant renal pelvic lesions occurring in the pediatric patient are discussed. The advantages and disadvantages of radical and conservative surgical approaches to these rare lesions are reviewed. Preoperative cystoscopy and retrograde pyelography are mandatory in all patients with renal tumors presenting with gross hematuria, regardless of age. Radical nephrectomy with total ureterectomy is recommended for Wilms tumor with extension into the collecting system.

Extrarenal and urothelial Wilms tumor

Two patients with Wilms tumor are presented. One patient had a bilateral Wilms tumor with invasion of the right renal pelvis and proximal ureter. A second patient presented with a large Wilms tumor originating separate from and inferior to the left kidney. The histologic, therapeutic, and prognostic implications of these radiographic presentations are explored.

Ureteral metastasis from Wilms tumor

Urothelial spread of Wilms tumor is uncommon and only 5 instances of ureteral metastases have been reported previously. A case of Wilms tumor with mid ureteral metastasis is presented and the literature is reviewed. Clinical implications and suggestions for surgical management are discussed.