growth - (pathology) an abnormal proliferation of tissue (as in a tumor)

adenomatous polyp - a polyp that consists of benign neoplastic tissue derived from glandular epithelium; "adenomatous polyps are visible protrusions that can develop on the mucosal surface of the colon or rectum"

sessile polyp - a relatively flat polyp

pedunculated polyp - a polyp with a stalk or peduncle