Perforated colonic cancers are not rare and leave patients at risk of developing peritoneal carcinomatosis. We present a 68-year-old male patient with a perforated transverse colonic tumour who underwent emergency extended right hemicolectomy. He made an uneventful postoperative recovery, and received adjuvant chemotherapy. Unfortunately, a routine positron emission tomography-computed tomography scan 16 months later demonstrated an fluorodeoxyglucose-avid nodule in the left scrotum associated with an irreducible left inguinal hernia that contained sigmoid colon. At laparotomy, the discovery of isolated peritoneal recurrence in the hernia sac was unexpected, given the absence of local recurrence in the region of the original transverse colon cancer perforation. The etiology therefore remains uncertain, but one may speculate that cell implantation occurred within the hernia sac at the initial emergency laparotomy.