Metastasis at the colostomy site: a rare case report.

Metastasis at the colostomy site is rare. Most reported patients with such metastases undergo abdominoperineal resection and this kind of metastases happened after a longer period post-cancer surgery. In our patient, because it happened during a short interval between rectal cancer surgery and stoma closure, colostomy site metastasis probably occurred owing to ablative cancer cell reflux and seeding from the obstruction during decompressive colostomy rather than local, lymphatic or haematogenous spread. Meticulous histologic analyses to rule out undetected, concomitant polyps and metachronous cancer are very important for patients with obstructive colorectal cancer who undergo decompressive colostomy. The potential risk of colostomy site metastasis during staged surgery for obstructive colorectal cancer remains uncertain; however, the result from this case report raises the question of such a risk for further studies in a greater number of patients.