Piriformis muscle metastasis from a rectal polyp.

Rectal cancers constitute over a quarter of all colorectal cancers. Spread of rectal cancer is usually to liver, lung and brain from high risk rectal cancers. Cases have rarely been reported of spread to soft tissue structures. Here we present a case of metastatic spread of a previously excised, early invasive adenocarcinomatous polyp to piriformis.