BACKGROUND: Pancreatic cancer is often locally and distally aggressive, but initial presentation as cecal perforation is uncommon. CASE PRESENTATION: We describe a patient presenting with pneumoperitoneum, found at initial exploration to have a cecal perforation believed to be secondary to a large cecal adenoma, after palpation of the remainder of the colon revealed hard stool but no distal obstruction. Postoperatively, however, the patient progressed to large bowel obstruction and upon reexploration, a mass could now be delineated, encompassing the splenic flexure, splenic hilum, and distal pancreas. Histological evaluation determined this was locally invasive pancreatic adenocarcinoma, and therefore the true etiology of the original cecal perforation. CONCLUSION: Any perforation localized to the cecum must be highly suspicious for a distal obstruction, as dictated by the law of LaPlace.