Symptomatic Ureteral Metastasis from Colon Adenocarcinoma

Abstract

Background: Symptomatic ureteral obstruction from a nonurologic metachronous metastatic malignancy is an unusual phenomenon that is underreported in the literature. This potential etiology for ureteral obstruction warrants consideration by the practicing urologist during a comprehensive evaluation as it may alter prognosis and management options for the afflicted patient.

Case Presentation: An 80-year-old Caucasian man with a remote history of prostate cancer and colon cancer presented with new unilateral ureteral obstruction characterized by hydronephrosis, acute kidney injury, and right-sided abdominal pain. A high clinical index of suspicion ultimately leads to the diagnosis of metastatic colon cancer on ureteral biopsy specimen.

Conclusion: Evaluation of symptomatic ureteral obstruction in a patient with a significant cancer history should include nonurologic malignant obstruction. Diligence in evaluation of the etiology of the ureteral stricture with repeat biopsies should be undertaken if there is clinical concern. Nephroureterectomy should be part of patient counseling for management of long segment malignant ureteral stricture disease.

Introduction and Background

Determination of the etiology of a ureteral stricture can be difficult in a patient with a complex oncologic, surgical, and radiation history. Initial management of obstructive ureteral stricture disease is appropriately centered upon decompression of the collecting system and diagnosis of the underlying problem. This is undertaken either endoscopically through placement and serial exchange of an indwelling ureteral stent, or by ipsilateral diversion with a percutaneous nephrostomy tube. Each offers the ability to delineate stricture characteristics through antegrade or retrograde fluoroscopic pyelography and can even be used in conjunction in the event of a narrow stricture. In addition, each allows for biopsy of the strictured segment so that an appropriate diagnosis can be determined. In this study we present a unique case of a distal ureteral stricture in a patient with a complex malignant, surgical, and radiation history. We sought not only to highlight options for the management of ureteral stricture disease but also to illustrate the importance of why perseverance in the identification of the underlying pathophysiology of the stricture is crucial for appropriate treatment of the underlying disease.

Presentation of Case

An 80-year-old man with a history of prostate cancer and colon cancer presented to the emergency department with right-sided abdominal pain and acute kidney injury. He underwent a radiographic work-up and was found to have new right-sided hydronephrosis with concern for mid-ureteral narrowing of unclear etiology. After counseling, he decided to undergo cystoscopy and right ureteral stent placement for decompression of his obstructed right collecting system. Of note, the patient had a pertinent surgical history of a remote radical prostatectomy with adjuvant radiation, as well as a right hemicolectomy (pT4aN0M0, stage IIB) with adjuvant chemotherapy 4 years before this encounter. Unfortunately, he also had known metachronous recurrence to omentum requiring laparoscopic omentectomy just over 1 year before presentation for urologic evaluation; however, follow-up imaging did not demonstrate any recurrent malignant disease. At the time of presentation for consideration of decompression of his collecting system, his PSA was <0.1 and CEA <1.0.

After initial decompression with the ureteral stent, the patient recovered well and his renal function normalized. On his subsequent two ureteral stent exchanges, biopsy of the strictured ureter was undertaken to rule out a malignant etiology given his malignancy history (Fig. 1). On his third stent exchange, a selective cytology was performed of his right collecting system, which was also negative. A subsequent cytology on his fourth stent exchange demonstrated atypical urothelial cells. This procedure was complicated by a urinary tract infection and obstruction of the ureteral stent requiring placement of a nephrostomy tube. On follow-up, a repeat biopsy was performed of the atypical appearing distal ureteral stricture, which demonstrated colon adenocarcinoma (Fig. 2). To further delineate the extent of the presumed metastatic disease, a CT-PET was performed demonstrating avidity limited to the distal right ureter (Fig. 3).

FIG. 1.

Right retrograde pyelogram demonstrating a dense right distal ureteral stricture and proximal filling defect similar to a “goblet sign.”

FIG. 2.

(Left to right: low power, high power, CK20 stain, and CDX2 stain) Ureteral biopsy specimen pathology analysis showing adenocarcinoma favoring metastatic adenocarcinoma of colorectal origin.

FIG. 3.

Representative coronal image of F18 FDG PET-CT scan demonstrating right distal ureteral avidity.

Given the unexpected pathologic finding and his oncologic history, he was discussed at both colorectal surgery and urology multidisciplinary tumor boards. In addition to observation, radiation, and medical management, he was also counseled on surgical options. Specifically, he was counseled on serial ureteral stent exchanges, nephrostomy tube placement, segmental resection, and nephroureterectomy. He was discussed at multidisciplinary tumor board, which agreed resection of known malignant disease was indicated. As such, given his pelvic surgical and radiation history, the surgical option that was deemed most suitable was a right nephroureterectomy. The patient wished to pursue a right nephroureterectomy and underwent a lysis of adhesions and robot-assisted laparoscopic right nephroureterectomy (Fig. 4). Intraoperatively, the distal ureter was dissected down to the intramural ureterovesicular junction, which appeared to be grossly normal upon inspection.

FIG. 4.

Upper left: laparoscopic view of enlarged and dysplastic distal right ureter; upper right: laparoscopic view of diseased right distal ureter at ureterovesicular junction; left lower: resected right kidney and ureter (white arrow: distal ureter with gross metastatic disease burden).

Final pathology analysis demonstrated colon adenocarcinoma comprising 7.5 cm of the distal ureter, extending through the ureteral wall and occluding the ureteral lumen. There was no evidence of malignant disease in his kidney, renal pelvis, or at the proximal/distal ureteral margins of the resected tumor. He recovered well from his procedure and his creatinine 3 months after surgery is 1.9 (GFR = 34 mL/min/BSA) from a baseline of 1.2–1.5 (GFR = 53 mL/min/BSA) preoperatively. As of the time of this article, he is tolerating an adjuvant course of capecitabine and bevacizumab.

Discussion and Literature Review

Metachronous metastasis from colonic adenocarcinoma to the ureter is both a rare phenomenon and underreported in the literature. Metastatic ureteral invasion is thought to occur from either periureteral adventitial infiltration causing ureteral compression, transmural infiltration, or mucosal infiltration.¹ Meticulous pathologic evaluation is vital for appropriate diagnosis. We would argue that these patients should be biopsied and evaluated in a systematic and serial manner in conjunction with the input of a multidisciplinary tumor board to ensure an appropriate diagnosis is made. Once a diagnosis has been made and the patient appropriately counseled, treatment approach must be carefully weighed. Colon adenocarcinoma is known to be a radiosensitive process; however, this approach must weigh the benefits of treatment of the malignancy with the not inconsequential side effects of possible potentiation of the stricture disease, impact to surrounding structures (pelvic vasculature in case of distal stricture), and patient quality of life. Surgically, previous case series have advocated for both radical nephroureterectomy² as well as segmental ureterectomy with ureteroureterostomy.³ The case series by Lee et al. included a patient with a distal ureteral stricture from metastatic colonic adenocarcinoma that underwent a ureteroureterostomy, but additional patient characteristics and history were not readily available that might influence a surgeon to proceed with this approach over a nephroureterectomy. In our patient, his prior pelvic radiation and surgical history, as well as the extent of the stricture disease as seen on preoperative radiographic work-up made a nephroureterectomy the more technically safe option. We would argue that in the rare cases of geriatric patients who present with metachronous metastatic colon cancer to the ureter who likely have a previous surgical and/or radiation history, surgeons should pursue radical nephroureterectomy.

Conclusion

Metachronous metastasis of colon adenocarcinoma to the ureter causing symptomatic ureteral stricture disease is a rare phenomenon. There is a dearth of literature to support appropriate management strategies for these patients. Perseverance in evaluation of ureteral stricture etiology in patients with significant oncologic history is crucial for appropriate diagnosis and treatment. Patients who present with long segment malignant ureteral strictures should be counseled on the possible treatment options, with radical nephroureterectomy included as a tenable and suitable technique for management.

Abbreviations Used

BSA

body surface area

CEA

carcinoembryonic antigen

CT-PET

computed tomography-positron emission tomography

GFR

glomerular filtration rate

PSA

prostate specific antigen

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received for this article.

Cite this article as: Moynihan MJ, Moinzadeh A, Mandeville JA (2020) Symptomatic ureteral metastasis from colon adenocarcinoma, Journal of Endourology Case Reports 6:2, 80–82, DOI: 10.1089/cren.2019.0134.