Partial obstruction of the sigmoid colon by surgical implantation.

Invasive transitional cell carcinoma of the bladder is known to extend directly to other organs in the pelvis. When metastases occur they almost always adhere to a rather consistent pattern of dissemination. We present an unusual case of partial obstruction of the sigmoid colon due to a metastatic transitiocellular bladder tumour four months after transurethral resection of the tumour complicated with a perforation into the peritoneal cavity. Direct implantation of the tumour with the resectoscope is the most possible explanation, but seeding on an intact serosa cannot be excluded either.