Resection of solitary abdominal wall metastasis of ascending colon cancer along the ventriculoperitoneal shunt: A case report

INTRODUCTION: Ventriculoperitoneal (VP) shunt is often placed as a treatment for hydrocephalus. Additionally, it is also not uncommon to perform laparoscopic surgery for colon cancer with a VP shunt in place. It is very rare for colorectal cancer to metastasize to an implanted VP shunt. We report a case of VP shunt-related metastasis of the ascending colon that was successfully resected. PRESENTATION OF CASE: A 79-year-old man who had a VP shunt for hydrocephalus two years earlier underwent laparoscopic right colectomy for ascending colon cancer. Six months after the colectomy, imaging examinations showed mass formation in the subcutaneous tissue of the abdominal wall along the VP shunt. Because of the possible metastasis of colorectal cancer and the fact that it was a solitary lesion, a tumor resection with replacement of the VP shunt was performed. Histopathological examination revealed that the mass was a metastasis of colon cancer. DISCUSSION: This case involves the metastasis of colorectal cancer in the subcutaneous tissue of the abdominal wall after laparoscopic surgery, and since the tumor had reached the serosa, the possibility of metastasis by pneumoperitoneum was considered. Careful intraoperative manipulation is considered to be important for prevention. CONCLUSION: Metastasis of colorectal cancer to the VP shunt is extremely rare, but possible. In such cases, intraoperative prevention and careful postoperative follow-up are required.