Under-stage and Overlook of Peritoneal Spread from Bladder Urothelial Carcinoma

Bladder cancer can spread from the sub-peritoneal space superior and posterolateral to the peritoneal cavity via the peritoneal lining. The aim of this study was to improve the identification of peritoneal spread from bladder urothelial carcinoma based on computed tomography (CT) scans.

This is a retrospective study including patients selected with the following criteria: (i) pathology-confirmed urothelial carcinoma; (ii) peritoneal spread identified on CT scans from axial and corona views, either initially or after radical/partial cystectomy, concomitant chemoradiotherapy (CCRT), or radiotherapy. One hundred and fifty-nine cases met the selection criteria.

Routes of spread to the peritoneum included the superior to anterior direction in 59 patients (37%), the superior to posterolateral direction in 19 (12%), and the superior to both anterior and posterolateral directions in 81 (51%). Invasion of specific sites included the abdominal wall in 101 patients (70%), bowel/mesentery in 84 (53%), prostate, uterus, and rectum in 30 (19%), and circumferential tumors that outlined the whole bladder wall in 59 (37%). Initial modes of therapy were chemotherapy in 86 patients (54%), cystectomy in 55 (35%), CCRT in eight (5%), radiotherapy in two (1%), and no therapy in eight (5%). Peritoneal spread due to under-staging (clinical/pathological stage) after local therapy was found in 84 patients (53%).

Initial pre-therapeutic staging is easily overlooked regarding peritoneal spread from bladder urothelial carcinoma. Combined axial and coronal views of CT scans can help identify peritoneal involvement.