Papillary tumor

A papillary tumor is a tumor shaped like a small mushroom, with its stem attached to the epithelial layer (inner lining) of an organ. It consists of papillae, which are outgrowths that consist of stroma with at least one central blood vessel, surrounded by epithelium. Usually, the epithelium constitutes the true tumor cells, and the fibrovascular cores (stroma and blood vessels) consist of reactive supportive tissue.