MSH: An adenocarcinoma containing finger-like processes of vascular connective tissue covered by neoplastic epithelium, projecting into cysts or the cavity of glands or follicles. It occurs most frequently in the ovary and thyroid gland. (Stedman, 25th ed),NCI: An adenocarcinoma with papillary growth pattern.,NCI: A morphologic variant of adenocarcinoma. It is characterized by the presence of a papillary growth pattern. Representative examples include thyroid gland papillary carcinoma, invasive papillary breast carcinoma, and ovarian serous surface papillary adenocarcinoma.