TUMORS OF THE URETER
Tumors of the ureter are uncommon, accounting for less than 1% of all genitourinary malignant lesions. They are seen twice as often in men as in women, and most patients are in the sixth or seventh decade of life at the time of diagnosis. Although there is no predilection to side, the lesion most commonly occurs in the lower ureter (70% of cases).
Etiology
The origin of these tumors is believed to be similar to that of other urothelial tumors. Schmauz aid Cole (1974) have shown that the relative risks for developing ureteral carcinoma are increased in cigarette smokers, coffee drinkers, and leather workers. Only at high-level exposure are the carcinogens apt to be active, since their transit time through the ureter is so rapid.
Pathogenesis & Pathology
Most tumors arising primarily within the intact ureter are transitional cell carcinomas (93%); only5K are squamous cell carcinomas. However, squamous cell carcinomas are seen more frequently when malignant disease develops in the stump of the ureter following nephrectomy for nonmalignant disease. Primary adenocarcinoma of the ureter is rare. When adenocarcinoma is found in the ureter, it is probably metastasis from the gastrointestinal tract, uterine cervix, lung, or prostate.
From 56 to 80% of ureteral tumors are papillary is opposed to solid. About 50% of the tumors are of iniei-mediate grade (II), and only 10% are of low grade, UK degree of anaplasia closely parallels the extent of invasion and is important in determining the prognosis,
Ureteral carcinomas spread to invade neighboring structures and organs (intestines, psoas muscle, iliac vessels); through the lymphatic to invade the pelvic, para-aortic, inguinal, and supraclavicular lymph nodes; and through the vascular to the lungs, bones, and liver. Distant metastases are usually observed within 2 years in all patients with regional lymph node metastases.
Tumor Staging
The staging system is based on surgical findings and is a modification of that suggested by Batata el. al.
A. Symptoms: The most common symptom is hematuria, which occurs in 59-99% of patients and is intermittent and sometimes quite profuse, pain is observed in 20-50% of patients. Passage of clots down the ureter causes acute and severe pain. Symptoms of bladder irritation (frequency, urgency, and dysuria) are reported in 10-52% of patients. Less frequently, as a result of metastatic disease, patients may complain of leg edema, pain from nerve root involvement, or constitutional symptoms. The tumor is silent in 12-26% of-patients and is discovered on excretory urograms.
B. Signs: Physical findings are usually absent. A palpable mass, caused by ureteral obstruction and the resulting hydronephrosis, is present in 7-50% of patients. If renal infection has supervened, the renal mass may be tender. Supraclavicular adenopathy or hepatomegaly may be felt if metastasis has occurred.
C. Laboratory Findings: Anemia may be found if bleeding is prolonged or severe. Gross or microscopic hematuria is usually present. Evidence of infection may be seen on urinalysis. If metastasis has occurred, the results of liver profile studies or the alkaline phosphatase level may be abnormal.
D. X-Ray Findings: The excretory urogram usually shows abnormal findings in all patients with carcinoma of the ureter. The 2 most common urographic findings are an intraluminal filling defect and hydronephrosis, with or without hydroureter. In many of patients, the kidney on the affected side is nonfunctioning and fails to visualize. Angiography is of little value because of the avascular nature of most such of tumors.
E. UItrasonography and CT Scanning: these procedures help to establish diagnosis.
F. Instrumental Examination: If the patient is bleeding, cystoscopy should be performed immediately in order to locate the source of the blood, during cystoscopy, the ureteral tumor is seen in 6-18% of patients. In these clients, biopsy confirms the diagnosis, catheterization, performed to collect urine for cytological examination and to better define ureteral lesion through retrograde ureterograms, is usually helpful in diagnosis. In retrograde studies, several signs have been considered diagnostic for ureteral tumors: (1) the Chevassu-Mock sign, ie, increased ureteral bleeding following manipulation at the site of the rumor; (2) Marion's sign, ie, drainage of clear urine after the ureteral catheter passes above the tumor; and (3) Bergman's sign, ie, coiling of the ureteral catheter in the distal area below the tumor. Usually, however, the occluding-tip ureteropyelogram remains the best method for demonstrating the nature and extent of the lesion.
G. Cytologic Examination: Urine should be collected either as a freshly voided specimen or through the retrograde catheter from the affected side prior to injecting the contrast medium. Unfortunately, cytologic studies, including those using retrograde dull urine collections, have significant (30%) false-negative results in patients with ureteral carcinoma. However, when the retrograde brushing technique de-veloped by Gill, Lu, and Bibbo (1978) is used, the material obtained and examined histologically and cytologically usually confirms the diagnosis of ureteral and is discovered on excretory urograms or cured by means of a Dormia stone basket (Kiriyama, Hironaka, and Fukuda, 1976).
Differential Diagnosis
Ureteral calculus may cause the same symptoms and signs as ureteral tumor if the calculus is radiolucent. The urogram in each instance shows a negative (black) shadow in the ureter and a dilated tract above it. Stone is suggested if a grating feeling is noted as a catheter is passed by it. Ultrasonography (Arger et al. 1979) or CT scanning should differentiate nonopaque stone from tumor. The correct diagnosis may be possible only at surgery. Ureteral stenosis, often secondary to compression by masses of lymph nodes involved by cancer (eg, cervical), can mimic ureteral tumor. CT scanning may reveal the involved nodes. A blood clot from a renal stone, a sloughed papilla, a renal adenocarcinoma, or a pelvic tumor also shows as a negative shadow within the ureter. The urograms should provide the differentiation. Air bubbles introduced through a ureteral catheter may be a source of confusion.
Treatment
A. Specific Measures: In the absence of demonstrable metastases, nephroureterectomy with resection of the periureteral bladder wall and adjacent vesical mucosa remains standard therapy. However, in patients with-noninvasive low-grade tumors of the lower ureter, distal ureterectomy with reimplantation may be considered (Johnson and Babaian, 1979). Partial ureterectomy for lesions located elsewhere in the ureter (middle- or upper-third) carries with it a high risk of tumor developing later below the line of resection therefore, local resection should be avoided. Resection of a tumor through a ureterotomy should be performed only for fibrous ureteral polyps (these are usually diagnosed by x-ray findings of a long, narrow, and generally smooth-filling ureteral defect without evidence of obstruction or renal damage).
Postoperative irradiation of the ureteral bed (4500 rads in 5 weeks) has been used successfully to reduce local recurrence in a small number of patients with high-grade invasive tumors of the distal ureter (Babaian, Johnson, and Chan, 1980). Radiotherapy has been well tolerated and has caused no long-term complications. Results of combination therapy for invasive tumors of the distal ureter, consisting of preoperative irradiation (5000 rads given in 25 fractions over 5 weeks) followed within 4-6 weeks by nephroureterectomy and excision of a bladder cuff, have likewise been encouraging, but further experience is still required.
B. Palliative Measures: If metastases are present, surgery is seldom justified unless it is required to relieve pain caused by obstruction or to control intractable bleeding. Radiotherapy, 6000 rads given in 30 fractions over 6 weeks, usually controls the local tumor. Chemotherapy is restricted to treating known metastatic lesions (lungs, liver, bones, etc); the drug programs parallel those in current use for patients with metastases from bladder cancer.
C. Follow-Up Care: The patient should be followed closely during the first several years to exclude local recurrences, visceral metastases, or late bladder tumors. Subsequent metastatic disease may be expected in approximately 40% of patients. In addition, the development of vesical malignant disease in more than 40% of patients requires that endoscopy be an integral part of the follow-up examinations. (See also the section on follow-up care for tumors of the renal pelvis, above.)
Prognosis
The prognosis for patients with ureteral carcinoma tends to be better than for patients with carcinoma of the renal pelvis (5-year survival rates of 67% and 53%, respectively), but the prognosis varies widely according to the grade of tumor and stage of disease. Patients presenting with metastatic disease usually die in less than 3 years.
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