A 37-year-old man presents to the emergency department with acute onset abdominal pain. Computed tomography (CT) of the abdomen and pelvis demonstrates a 3.5-cm mass in the transverse colon associated with bowel obstruction. CT of the chest is negative for metastatic disease. He is taken to the operating room and undergoes resection of the mass. Pathology confirms a 4 × 3.8 cm adenocarcinoma with extension into the muscularis propria, 3/17 positive nodes, and uninvolved proximal, distal, and radial margins. Tumor is found to be proficient in mismatch repair (MMR). The patient recovers and is discharged. He is referred to medical oncology for further management.