Pathomorphological quality assessment of complete mesocolonectomy in right colon cancer

Complete mesocolonectomy (CME) is the current standard of treatment for colon cancer patients. At the same time, there are currently no clear standards for the pathomorphological assessment of CME quality, allowing for a comprehensive and independent assessment of the quality of surgical treatment. Objective. Creation of a standardized system of pathomorphological assessment of the quality of TMCE based on the developed set of universal criteria. Material and methods. The prospective study included the results of treatment of patients with adenocarcinomas of the right half of the colon, who underwent surgical interventions in the volume of right-sided hemicolectomy (RSHE) in the period from 2022 to 2024. The method of pathomorphological examination included mandatory photo documentation, as well as mesocolonectomy quality assessment using the classification of N. West et al., visual assessment of CME quality using the classification of S. Benz et al., standard microscopic examination to determine the presence of metastatic lymph nodes (LN) lesions, dividing them into groups according to the Japanese classification. Results. The study included 142 patients, 116 (81.7%) of whom underwent laparoscopic interventions, while 105 (73.9%) had D3 lymphodissection. According to the pathomorphological study, the most common (65 cases — 45.8%) tumors were located in the ascending section of the transverse colon, multicentric tumor growth within the colon was detected in 3 (2.1%) cases. The overwhelming majority of patients had stage III (92 patients — 64.9%) and IV (25 patients — 17.6%) clinical stages of the disease. The median of the studied LN was 48 (12—225), affected — 3 (1—51) LN. LN lesion was detected in 79 patients (55.6%). Damage to the apical LN was found in 9 (6.3%) cases. Unfavorable prognosis factors (perineural growth, lympho-and angiovascular invasion, the presence of tumor deposits and metastases in the lung) were identified in 92 (64.7%) patients. Good quality of mesocolic fascia isolation (Grade 3) according to West was found in 101 cases (71.1%), true CME (Type 0 according to Benz) was performed in 74 cases (52.1%). Conclusion. The quality assessment of the removed specimen after RSHE should be based on a detailed examination of all removed lymph nodes with division into groups in accordance with the Japanese Clinical Classification, assessment of the plane of intestinal resection according to N. West and the quality of CME according to S. Benz. © 2025 Elsevier B.V., All rights reserved.