Gastrointestinal: Recurrent urothelial cancer of the remnant ureter invading the ileal conduit: PET/CT imaging

Abstract

Gastrointestinal: Recurrent urothelial cancer of the remnant ureter invading the ileal conduit: PET/CT imaging A 68-year-old man complained of hematuria for three months. His past history was remarkable for urinary bladder cancer treated initially with cystectomy and ileal conduit urinary diversion, and nephroureterectomy 5 years later from high-grade urothelial carcinoma of the right renal pelvis and right ureter. For the present hematuria 6 years after the right nephroureterectomy, 18 F FDG PET/CT demonstrated a hypermetabolic lesion of the right ureteral stump with involvement of the uretero-ileal anastomosis and ileal conduit ( Fig. 1). Contemporary CT showed a 2.9 × 5.8 × 2.3 cm tubular mass in the lower right retroperitoneum extending as a filling defect into the ileal conduit. PET/CT and CT exams were consistent with a recurrent urothelial carcinoma confirmed by tissue sampling (Figs 1, 2a). The patient received 2 cycles of carboplatin and gemcitabine neoadjuvant therapy with a favorable response as evidenced by a significant reduction of the ureteroileal lesion (Fig. 2b). Subsequent radiotherapy was planned.Standard practice for patients with bladder urothelial carcinoma with invasion into the muscularis propria is cystectomy. There are many surgical approaches to urinary diversion. One of the most common is the ileal conduit, a procedure in which a 15-cm portion of the ileum is diverted, thus creating a reservoir for urine. The ureters are then anastamosed to the proximal end of this conduit. Patients with cystectomy have a local tumor recurrence rate of 3-16%. One longitudinal study found the tumor re-occurrence rate involving the upper tract to be 4% at 3 years and 7% at 5 years after cystectomy. In another multicentric retrospective study patients with ileal urinary diversion were found to have a secondary tumor rate involving the ileal conduit of .02%. The study also suggested that ileal conduit diversion has a lower rate of cancer recurrence than colonic diversion methods of urinary diversion. Unlike many other post-cystectomy diversion methods, where the secondary tumor recurrence is often gastrointestinal in origin, ileal conduits were found to be almost exclusively urothelial in origin. Additionally, most of the recurrences occurred at the site of uretero-ileal anastomosis.PET/CT is usually limited for the evaluation of urinary malignancy involving the urinary tract because of presence of physiologic 18 F FDG urine activity interfering with the detection of any potential tracer-avid lesion. The use of forced diuresis with furosemide and delayed PET/CT imaging may be effective, in certain instances, in un-masking underlying hypermetabolic urothelial diseases. In our case, the remnant right ureteral stump, free of any urine, offers an excellent target-to-background activity ratio for the FDG-avid tumor with extension to the uretero-ileal anastomosis and ileal conduit. These PET features correspond to the tumor filling defects seen on contemporary CT. Figure 1 Fused PET/CT images (in the axial, sagi...

Carcinoma arising in ileal conduit or orthotopic ileal neobladder reconstruction: A 20‐year single institute experience

“…Cases of malignancy in urinary diversions involving the ileum are extremely uncommon, with a limited number of well‐documented cases published in English literature, the majority of which are individual case reports and a few case series (Tables 2 and 3). 4,7,9–43 Urinary bladder augmentation poses a greater risk of late uroenteric cancer compared to the ileal conduit or ileal replacement of the ureter 2,4,7 . New primary malignancies that develop after bladder augmentation are typically found near the ileovesical anastomosis 2 .…”