The incidence of transverse colon cancer is low and surgery for transverse colon cancer is technically demanded. The anatomical structures that are relevant during transverse colon cancer surgery include: firstly, complicated structural variations in the vascular anatomy of the transverse colon and its implications for D3 lymph node dissection. Root positioning and ligation of the middle colic artery (MCA) as well as right colic artery (RCA) if exists should be performed to remove No. 223 lymph nodes, with an understanding of the variations in the vascular anatomy of MCA, accessory MCA, RCA, Henle's trunk, jejunal vein, and inferior mesenteric vein. Secondly, the transverse colon is located in the center of gastrula rotation during embryonic development, which resulted in complexity in fascia anatomy. However, mobilization of the splenic flexure and/or hepatic flexure colon would frequently be necessary to ensure a tension-free anastomosis. Understanding its embryonic development process as well as the root of transverse mesocolon would be beneficial for an efficient splenic flexure mobilization with "three-way encirclement". Thirdly, the transverse colon, which originates from the midgut and hindgut, and the gastrocolic ligament and greater omentum, which originate from the mesogastrium and mesoduodenum, are intertwined. The above-mentioned topological structure resulted in a difficulty in gastroepiploic lymph node resection, which was recommended for selected advanced cases with T3~T4 stage. Lymph node dissection may not be performed in patients with T1~T2 stage.Thus, it is of great importance to understand this topological structure area, especially the anatomical landmark of the space between transverse mesocolon and mesogastrium.