Summary
A case of adenocarcinoma occurring in a hyperplastic (metaplastic) polyp of the colon
is presented. The polyp, two cm in diameter, was located in the transverse colon of
a 45-year old male patient, and was removed endoscopically. From the periphery to
the centre, the polyp showed epithelial changes progressing from hyperplastic to severely
dysplastic, terminating in a central focus of invasive adenocarcinoma. It is suggested
that the considerable number of absorptive cells in large hyperplastic polyps may
occasionally result in an excessive absorption of carcinogen thus leading to dysplastic
changes.
Key words:
Adenocarcinoma - Colon - Dysplasia - Hyperplastic polyp
