Morphologic Progression of Pedunculated Submucosal Invasive Colon Cancer

To clarify the morphologic progression ofpedunculated submucosal invasive colon cancers, weassessed the morphologic changes in 50 such cancersaccording to the volume of cancer in the submucosallayer. The shape of the head of the polyp was definedat the widest slice as round, concave, or semicircularwith a horizontal head (SHH). As the cancer invaded thesubmucosa, the peduncle of the submucosal invasive cancer thickened and the structure of the headprogressively collapsed, causing its shape to changefrom round to concave to SHH. The proliferating cellnuclear antigen (PCNA) expression (labeling index, LI), determined at the deepest point ofsubmucosal invasion, showed a significant correlationwith the morphologic progression among round, concave,and SHH cancers as 36.4 ± 12.1%, 42.3 ±11.8%, and 62.1 ± 12.5%, respectively (P <0.05). Results indicate that the PCNA-LI may be a usefulmarker for the morphologic progression of pedunculatedsubmucosal invasive colon cancers.