Clinicopathologic Review of Malignancies in Neobladders and Conduits Following Bladder Reconstruction.

Malignancy associated with ileal neobladders or ileal conduits in postradical cystectomy patients is rare. Yet, recurrent urothelial carcinoma or new primary cancers, such as adenocarcinoma, enteric type (EA), are potential complications that pose significant clinical challenges. This study aimed to evaluate the incidence, clinical outcomes, and management strategies for malignancies in patients with ileal neobladders or ileal conduits. A retrospective review was conducted at 3 large academic institutions, identifying 10 cases of malignant tumors arising in ileal neobladders or ileal conduits over a period of 10 years. The study cohort included 9 male and 1 female patient aged 56 to 92 years (mean age = 68.2 y). Data on clinical presentation, management, pathology, and outcomes were collected, with a focus on recurrence and disease-specific survival rates. Seven of 10 patients (all males) were initially diagnosed with invasive high-grade urothelial carcinoma (IHGUC), whereas 3 patients had a history of bladder augmentation with colonic tissue (BA) for benign etiologies. Of patients with IHGUC, 2 patients received neoadjuvant chemotherapy, 1 received a combination of chemotherapy agents, and 3 patients underwent intravesical BCG therapy. All IHGUC exhibited conventional morphology without divergent differentiation. Pathologic staging of the cystectomy for IHGUC ranged from pTa to pT3a, with 4 cases showing lymph node metastasis. IHGUC recurrence was detected in 6 of 7 patients with a latency period range of 7 months to 6.7 years (mean 37 mo) and all tumors again exhibiting conventional morphology without divergent differentiation. IHGUC recurrence demonstrated a pathologic stage ranging from pT2 to pT4, and 5 died (mean = 4.2 mo), whereas 1 patient remains alive and on surveillance. EA occurred in 4 patients, including 3 BA patients and 2 foci in 1 patient with a neobladder for IHGUC. Staging of patients with EA ranged from pTis to pT2 developing 31 to 55 years postsurgery. Three of 5 EA cases were associated with a precursor lesion including 2 tubular adenoma with high-grade dysplasia, and 1 sessile serrated lesion with dysplasia. EA patients had relatively favorable outcomes compared with IHGUC patients,  with all surviving patients currently on surveillance though with one case demonstrating nodal metastasis. Although rare, malignancies in ileal neobladders or ileal conduits are a serious complication. Although IHGUC recurrence often leads to poor survival, EA patients-especially those with prior bladder augmentation-seem to be associated with better survival outcomes. The long latency period for IHGUC recurrence and the favorable prognosis for EA underscore the need for vigilant long-term surveillance.