Contact invasion by a polypoid pseudosarcomatous carcinoma of the esophageal wall: report of a case.

We present herein the interesting case of a 43-year-old man in whom a rapidly growing polypoid tumor of the esophagus was histologically proven to be pseudosarcomatous carcinoma. Of particular interest was the unusual type of invasion displayed by this tumor, whereby the head of the polyp came into contact with and directly invaded the esophageal wall at the distal end of the pedicle to the submucosal layer, while invasion near the stalk was restricted to the mucosa. This style of invasion is considered to be caused by the mechanical pressure produced by the rapid growth of the tumor in the narrow esophageal lumen.