bowler hat sign

A term referring to the spreading of barium contrast around an adenomatous or villotubular colon polyp, at the base of which there is a recess between the stalk and the polyp ‘body’, forming the hat’s ‘crown’
DiffDx Benign—leiomyoma, lipoma, hyperplastic polyp, premalignant; malignant—leiomyosarcoma, lymphoma, melanoma

bowler hat sign

GI radiology Spreading of barium contrast around an adenomatous or villotubular colon polyp, at the base of which there is a recess between the stalk and the polyp 'body', forming the hat's 'crown' DiffDx Benign-leiomyoma, lipoma, hyperplastic polyp, premalignant; malignant–leiomyosarcoma, lymphoma, melanoma