Metastasis from a pedunculated adenomatous colonic polyp with focally invasive carcinoma: report of a case.

A patient who had metastasis from a focus of invasive carcinoma confined to the head of an otherwise benign pedunculated adenomatous polyp of the sigmoid colon is described. That only 20 such cases have been reported previously attests to the rarity of this phenomenon. Because the morbidity and mortality of radical surgery far outweigh the liklihood of metastasis from such foci of invasive carcinoma in pedunculated adenomatous colonic polyps, local removal is recommended.