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

Context: Carcinomas found in urinary diversion specimens are uncommon, particularly new primary tumours. New primary tumours primarily occur when the large intestine is utilised, whereas the occurrence is infrequent with the use of the ileum. These tumours include both the recurrence of primary malignancy or the development of a new primary malignancy originating from the small intestine. Design: A search was performed within the pathology laboratory system to identify cases of malignancies involving ileal conduit/reconstruction from 2002 to 2022. Data on demographics, clinical details, pathology and management was recorded. Results: A total of 13 male patients, with a mean age of 67 years (range = 49–81 years) were included in the study. The initial procedure performed included cystoprostatectomy (n = 10, including one case with right nephroureterectomy) and cystectomy (n = 3, including one case for bladder exstrophy) for initial diagnoses including urothelial carcinoma (n = 11; conventional, 6; sarcomatoid, 1; glandular 1; plasmacytoid, 1; micropapillary, 2) and adenocarcinoma (n = 1). The initial management included radical surgery with neoadjuvant chemotherapy/immunotherapy (n = 1), adjuvant chemotherapy (n = 3), intravesical adjuvant BCG (n = 2) and intravesical adjuvant chemotherapy (n = 1). Malignancies in ileal conduit or orthotopic ileal neobladder included recurrent urothelial carcinoma (n = 10) and new secondary adenocarcinomas (n = 3), which developed as early as 3 months (usually recurrence) and up to 13, 33 and 45 years (new primary malignancy) following primary resection. Conclusions: Utilising the ileum as conduit/neobladder presents a viable alternative for urinary diversion with a reduced malignancy risk compared to using a segment of the large intestine. However, there remains a potential for malignancy, either tumour recurrence or a new primary malignancy. In our study, tumour recurrence occurred up to 4 years following the initial diagnosis and the development of a new primary malignancy occurred up to 45 years after the initial diagnosis. Consequently, it is crucial to prioritise long‐term follow‐up for these patients undergoing this procedure. [ABSTRACT FROM AUTHOR]