Early drain site tumor recurrence post adjuvant chemotherapy for locally advanced colon carcinoma: Case report and literature review.

Introduction: Colon carcinoma is the most common type of gastro-intestinal cancer. Despite radical surgery, locoregional recurrence has been observed in 4-11.5 % of patients. Abdominal wall metastasis at the drainage site is an extremely rare finding and only a few cases are described in the literature. The mechanism of this metastasis is unknown, and its management remains unclear due to the rarity of the condition.

Case Presentation: A 66-year-old patient underwent left colectomy for locally advanced colonic adenocarcinoma. Eight months after the end of adjuvant chemotherapy, the patient complained of a progressive mass of the left lumbar centered on the previous drain site scar. Abdominal wall recurrence was suspected. The patient had R0 mass excision. Histopathologic examination showed a parietal infiltration by a colloid adenocarcinoma. The patient underwent adjuvant chemotherapy. No recurrence was observed.

Discussion: Since 1999 only six cases of colon cancer drainage site metastasis have been reported. Metachronous solitary abdominal wall metastasis after radical colectomy may occur via cancer cell implantation, lymphatic or hematogenous route, or direct invasion. In case of drain site metastasis, the most likely hypothesis is the implantation of tumor cells into the abdominal wall through the drainage route performed during surgery.

Conclusion: The appearance of abdominal wall mass after colon cancer resection must always be considered suspicious. To reduce the risk of abdominal wall metastasis we recommend minimizing tumor manipulation, resection the route of previous percutaneous drainage and performing a radical surgery. Metastasis resection combined with chemotherapy is the appropriate approach to treat these metastases.