Cover legend: Upper Panel: Micropapillary carcinoma. (A) Low power image demonstrating nearly exclusive micropapillary architecture often, which on high power reveals (B) multiple nests with high-grade nuclei filling lymphatic-like clear spaces. Lower Panel: (A) Serrated adenocarcinoma shows infiltrative glands with a serrated contour. (B) Adenoma-like adenocarcinoma resembles a villous adenoma despite extending into the wall of the colon. (C) Adenosquamous carcinoma shows an admixture of malignant squamous and glandular elements. (D) Undifferentiated carcinoma manifests as sheets of highly malignant epithelioid cells. (Case courtesy of Michael M Feely).