Polypoid invasive carcinoma of the gallbladder‐Another challenging polypoid neoplasm‐

Invasive gallbladder carcinoma generally presents as nodular-sclerosing growth. Recently, "polypoid invasive carcinoma (PICA)" showing grossly visible polypoid neoplasm and histologically invasive carcinoma with no adenomatous components was proposed as a neoplastic polyp of the gallbladder.We herein report five cases of PICA collected from 49 cases of invasive gallbladder carcinoma in comparison with another polypoid preinvasive neoplasm of...