Adenocarcinoma of an ileal conduit developing 8 years after cystoprostatectomy for locally advanced prostate carcinoma

Abstract

A 70-year-old patient was treated in September 2017 for a malignancy in an ileal conduit (IC) which he received in 2009 for the treatment of prostate cancer. The tumour was found incidentally during a routine sonography. A CT scan revealed a mass near the IC. An endoscopy with biopsies showed an intraepithelial neoplasia of the ileal mucosa in the IC. We performed a segmental ileal resection. Histological findings revealed an ileal adenocarcinoma. The postoperative course was uneventful. The patient has remained alive without tumour recurrence up to the most recent negative CT screening in April 2019. Secondary malignancies after urinary diversions are a well-known complication, including procedures using small bowel parts for the urinary diversion. Adenocarcinomas arising in an IC are rarely described in literature. Concerning said tumour entity, surgical removal is often recommended. There is no evidence for the success of chemotherapy or radiation due to insufficient clinical trials. When diagnosing a mass in an IC, a secondary malignancy should be taken under consideration.

Background

Secondary malignancies after urinary diversions are a well-known complication, including procedures using small bowel parts for the urinary diversion. Even if the exact mechanism is not fully understood, it is believed that the chronic exposure of urine to the intestines may lead to a dysplasia and a malignancy in the long term. The recommended treatment for said malignancies includes the primary resection of the affected bowel segment. There is no valuable data about the benefit of radiation or chemotherapy, nor of the treatment of an advanced tumour stage.

This report describes a case of a secondary malignancy that developed in an ileal conduit (IC), which was successfully surgically removed.

Case presentation

A 70-year-old patient was treated in our hospital in November 2017 due to a carcinoma that had developed in the IC. The primary diagnosis that led to the conduction of the IC was a prostate carcinoma diagnosed and treated in 2009 (tumour, node, metastases (TNM) classification: pT4a pN1 L1 V0 Pn1 Rx, Gleason 5+5=10). The operative procedure, a pelvic exenteration, was comprised of a cystectomy, a prostatectomy and a rectal extirpation, with the supply of an IC and an end colostomy.

His medical history includes a parastomal hernia, hypertension, a nasal basal cell carcinoma, as well as a temporal squamous cell carcinoma.

In September 2017 during a routine sonography occurring every 3 months, hydronephrosis along with minimal dilatation of the renal pelvicalyceal system was found, implying a hydroureteronephrosis. The patient did not show any associated symptoms. The physical examination did not reveal any pathological findings, except a parastomal hernia.

Furthermore, the laboratory testing showed no elevation of prostate-specific antigen (PSA) (0.009 ng/mL). While hydronephrosis was seen multiple times, we performed a full staging CT scan. A suspicious 3 cm sized mass near the IC was revealed. Distant metastasis and a lymphadenopathy were not detected (figure 1).

Figure 1.

Abdominal CT scan. visible is a 30×30×45 mm sized mass of the ileal conduit. Lymphadenopathy is not visible.

As the mass raised suspicion and could not be properly identified, a conduitoscopy with biopsies was performed. The histopathological examination revealed a high-grade intraepithelial neoplasia of the ileal mucosa developed in the IC (figure 2). Immunohistochemically, a focal expression of cytokeratin 20 (CK 20) was detected without any expression of androgen receptors, PSA, or cytokeratin 7.

Figure 2.

Preoperative specimen shows a tubulovillous neoplasia (H&E staining, magnification 40×).

Histologically, there was no correlation to the prostate cancer that was diagnosed in 2009. Our urological tumour board unanimously decided to perform a segmental ileal resection due to the history of a previous carcinoma.

Treatment

Based on the decision of our interdisciplinary tumour board, we performed an explorative laparotomy, where we found the suspicious mass 10 cm distally located from the IC, away from the ureteroileal junction itself. We resected the affected ileal segment, reattached the ileum and implanted a ureteral stent on the right side to ensure urinary flow. Intraoperatively, six local lymph nodes were resected, which did not show any sign of metastasis histologically. The histological examination of the surgical specimen revealed an invasive carcinoma developed in the IC due to the transformation of ileal mucosa to adenoma and subsequently to an adenocarcinoma (figures 3 and 4).

Figure 3.

The specimen shows an adenoma (black cross), as well as an invasive carcinoma with infiltration of the lamina propria (H&E staining, magnification 20×).

Figure 4.

An ileal specimen with infiltration of all wall layers (H&E staining, magnification 20×).

Outcome and follow-up

The patient has remained alive without tumour recurrence up to the most recent negative CT screening in April 2019. A mild hydronephrosis can be seen bilaterally, the patient does not describe any associated symptoms. The ureteral stent remains on the right side to ensure sufficient urinary flow.

The decision of a prolonged stent drainage was based on individual circumstances, not based on the standard of care. The possibility of a recurrent increasing hydronephrosis that could impact the patient's kidney function led to the decision of the prolonged stent drainage. The patient did suffer from recurrent hydronephrosis, which is also often seen with reimplanted ureters. Nevertheless, a precautious decision regarding the prolonged stent drainage was made. Currently, the patient is under the surveillance of the urology department, where he receives an ultrasound screening every 6 months, as well as a CT screening every 12 months.

Discussion

Whereas primary small bowel tumours are rare, it is known that urinary diversions blending the urinary and intestinal tracts lead to an increased incidence of secondary malignancies.

There are several studies that implicate a higher incidence of cancer development after urinary diversion procedures.¹

The highest incidence of a secondary malignancy that is published in literature is seen after the ureterosigmoidostomy procedure as stated by Bell et al.² This might be caused by the fact that this was the most commonly used technique of urinary diversion in the past. Regarding an article published by Przydacz et al in 2018, said procedure shows a recent resurgence of interest.³ It might be due to its advantages over intestinal conduits, including urinary continence, a good quality of life, a high patient acceptance rate and a rapid performance rate.³

The incidence of colon adenocarcinoma in ureterosigmoidostomy is 100-fold to 550-fold higher in comparison to the general population, which translates into an incidence of 2%–15%.⁴ The risk of any neoplasia after ureterosigmoidostomy is 22% at 20 years, as stated by Woodhouse.⁵

A study form 2002 by Ali-El-Dein showed a tumour development in 0.3% out of 350 patients with an IC.⁶ Similarly, Kälble et al showed a low incidence of the development of adenocarcinoma developing in an IC.⁷

The incidence of secondary malignancies seems to be lower in the more recently performed procedures, such as an IC. This may be due to the fact that these procedures are considered incontinent diversions where urine does not remain in constant contact with the bowel mucosa. Contrarily, continent diversions, such as ureterosigmoidostomies allow a constant contact of urine with the bowel mucosa, which shows a higher incidence of secondary malignancies. The lower incidence of developing cancer in an IC compared with other urinary diversions is described in a study by Bedeir et al from 2002.⁸

Even though the exact mechanism is not fully understood, the higher incidence might be associated with the fact that a chronic exposure of colonic mucosa to urine causes chronic inflammation and irritation. This chronic inflammation and irritation may lead to a dysplasia and therefore in the long term to the development of cancer.

These secondary malignancies are described with a wide clinical presentation, whereas gross hematuria is the most common initial symptom.⁹

Mizusawa et al treated a 78-year-old woman who developed an adenocarcinoma in the IC. She received the IC due to an invasive bladder carcinoma. She presented with abdominal pain as the dominant symptom. The patient passed away just 1.5 months after admission due to renal failure.¹⁰

While most cases described in literature talk about the supply with a urinary diversion due to the diagnosis of bladder cancer, the development of an adenocarcinoma arising in an IC after a radical procedure for invasive prostate carcinoma has not been reported previously.

Regular endoscopic screenings may be beneficial, even though there are no strict guidelines.

The treatment of choice includes the primary resection of the affected bowel segment, as well as the mesentery for a localised malignancy.¹¹ Data about the use of chemotherapy or radiation do not seem to be reliable.^{12 13}

Learning points.

• The development of an adenocarcinoma after a urinary diversion combining the urinary and intestinal tracts is a well-known phenomenon.

• Even though there is a risk for developing an adenocarcinoma in an ileal conduit, it seems to be lower than in continent diversions.

• In absence of clear guidelines on screening of ileal conduits for malignancy, endoscopic screening may be explored as an option similar to that in an orthotopic neobladder.

• Primary resection may be offered to patients with a mass localised in the ileal conduit and an absence of lymphadenopathy