Unexplained neoplastic anastomotic recurrence after right hemicolectomy: a case report

Background: Anastomotic recurrences of the colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. In this paper, a case of unexpected early local recurrence after surgery for colon cancer is presented. Case presentation: A 68-year-old Caucasian man underwent right hemicolectomy for invasive G2 adenocarcinoma. Two months later, endoscopy revealed a wide and well-functioning anastomosis with a hyperemic, hard, and thickened mucosal area of about 2 cm in diameter. Biopsies showed the presence of an adenocarcinoma with the same grading of the previous lesion. Ten days later, the patient underwent a new intervention; the last 10 cm of the ileum and half of the remaining transverse colon were resected, and the patient started adjuvant therapy. Specimen examination confirmed the presence of an adenocarcinoma (G2) penetrating the muscular layer of the wall; also, in this case, resection edges were free from tumoral invasion, and the removed lymph nodes were exempt from neoplastic colonization. The patient was seen in follow-up for about 5 years, and he did not show local or systemic manifestations. Conclusions: Whenever a neoplastic recurrence on the anastomotic line occurs, in the presence of negative intestinal margins, as usual in right colectomies, the implantation of neoplastic cells could be the possible cause.