SURGICAL CYTOREDUCTION OF PERITONEAL METASTASIS DUE TO RIGHT COLON ADENOCARCINOMA IN A PATIENT WITH LYNCH SYNDROME – CASE REPORT

Case Presentation A 36-year-old male underwent a right colectomy for acute appendicitis in December 2022. The biopsy revealed colon adenocarcinoma, with immunohistochemistry showing microsatellite instability and loss of MLH1 and PMS2 repair protein expression, confirming a diagnosis of Lynch Syndrome. The patient received chemotherapy cycles (5-Fluorouracil and leucovorin) and was referred to the colorectal team due to a large, expansive peritoneal lesion in the right iliac fossa. The lesion measured 8.5 × 7 × 9 cm, with no cleavage plane from adjacent intestinal loops and the psoas muscle. There was an unclear cleavage plane involving a small portion of the right common iliac artery, affecting less than 30% of its circumference, and another peritoneal lesion near the umbilical scar. A joint colorectal and vascular surgery approach was performed, achieving complete cytoreduction of the right iliac fossa lesion. The procedure included a segmental enterectomy with primary anastomosis, partial resection of the psoas muscle, and resection of umbilical peritoneal metastasis. There was no vascular invasion, and the surgery was completed without complications. The patient showed good postoperative progress, being discharged on the sixth day of hospitalization. Follow-up revealed decreased CEA levels and no signs of recurrence.

Discussion Lynch Syndrome is the most common hereditary condition linked to colorectal cancer. Identifying these patients is crucial due to the more than 80% lifetime risk of colorectal cancer, often diagnosed at advanced stages, as in the case presented. Peritoneal metastases significantly reduce overall survival and are associated with a poor prognosis in 30-40% of cases. In selected patients, surgical cytoreduction, either alone or combined with HIPEC, can improve oncological outcomes. This approach should consider the peritoneal carcinomatosis index (PCI) and the feasibility of complete cytoreduction. In the presented case, the presence of a limited number of lesions, despite their large size, allowed for a successful surgical approach.

Conclusion Even in patients with advanced disease and peritoneal metastases, if the PCI is below 20 and complete cytoreduction is achievable, surgical intervention should be considered as a definitive management strategy. This approach can improve oncological outcomes, increasing survival and quality of life for affected patients.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025