Urothelial Tumors of the Renal Pelvis and Ureters

Urothelial Tumors of the Renal Pelvis and Ureters

Urothelial tumors are tumors that involve the urinary system. They are found in the renal pelvis, the urinary bladder, ureters and the urachus. The ureteral tumors are the most common of the urothelial tumors while the tumors of the renal pelvis account for just 5% of all Urothelial tumors.

Frequency of Urothelial Tumors

In the western world, the incidence of urothelial tumors is two per 100,000 people. The mean age for getting affected by this type of tumor is 65 years. Urothelial tumors of renal pelvis and ureters (upper tract Urothelial tumor) are more common in males with the male to female ratio of incidence being 3:1.
60% of the urothelial tumors of the upper tract are invasive in nature.

Causes for Urothelial Tumors

• Tobacco smoking is the single most important cause behind the development of these tumors. 70% of urothelial tumors of renal pelvis and ureters in men and 40% of these tumors in women are directly associated with smoking.
• Drinking more than seven cups of coffee per day is said to increase the risk of these tumors.
• Long term analgesic abuse, especially of phenacetin can increase the risk of urothelial tumors of the upper tract by as much as 70%.
• Exposure to chemicals like plastics, petrochemicals and tar in industries increase the risk of these tumors.
• Exposure to cyclophosphamide is linked with development of high grade tumors.
• Heredity is also believed to play an important role.

Types of Urothelial Tumors

95% of all upper tract urothelial tumors are transitional cell carcinomas. Squamous cell carcinomas constitute 1% to 7% of these tumors and are usually associated with staghorn calculi. Adenocarcinomas constitute less than 1% of urothelial tumors.

Symptoms of Urothelial Tumors

• The most common symptom of urothelial tumors of renal pelvis and ureters is gross or microscopic hematuria. It is seen in 75%of all cases.
• 20% of the patients complain of pain in the flanks. It may be a result of gradual obstruction of the urinary passage or because of an acute colic resulting from an obstruction caused by a blood clot.
• In 10-20% of patients, a distinct mass can be palpated in the lumbar region.
• Painful micturition is seen in 6% cases.
• In advanced cases, the patients complain of loss of appetite, weight loss or even bone pain.

Staging of Urothelial Tumors

The WHO staging is based on the aggressiveness of the tumor. It can be papillary urothelial neoplasia, low grade carcinoma or high grade carcinoma.
The TNM classification is based on the extent of spread of tumor.

Treatment of Urothelial Tumors

As per the guidelines laid down by the European Association of Urology, conservative treatment is reserved only for the following cases:

• Tumor is unifocal
• The size of tumor is less than 1 cm
• Biopsy shows that it is a low grade carcinoma
• No evidence of any metastasis.

Patients with low grade superficial lesions are ideal candidates for segmental ureterectomy and endoscopic therapy.
Nephro-ureterectomy with excision of bladder cuff is indicated in case of renal pelvis urothelial tumors with

• a high volume
• a high grade
• a high stage
• extensive disease

 
Reference:
https://emedicine.medscape.com/article/452449-overview