Pathology of the malignant colorectal polyp: Issues in morphologic criteria and recommendations from the Italian Group of Gastrointestinal Pathologists

Malignant colorectal polyps (MCPs) are early-stage colorectal cancers (CRC) generally diagnosed following endoscopic removal of otherwise bland lesions. Due to nodal metastatic potential and risk of residual disease, diagnosis and risk stratification of MCPs are critical for determining appropriate clinical management, which can range from clinical/endoscopic/imaging follow-up to radical surgery with locoregional lymphadenectomy. Although a dedicated multidisciplinary team should discuss this decision, the MCP histopathologic assessment is crucial and raises several issues. Following productive discussions that occurred in dedicated meetings and educational activities, the Italian Group of Gastrointestinal Pathologists have developed these recommendations for the histopathologic assessment and multidisciplinary management of MCPs, addressing diagnostic challenges and proposing standardized criteria. This document is based on a comprehensive review of the literature and opinions from pathologists with dedicated gastrointestinal experience. Key topics include pre-analytical specimen handling, histopathologic criteria for MCP diagnosis, and assessment of histopathologic features associated with MCP high-risk behavior. The role and integration of features inferred from advanced CRCs, such as mismatch repair protein status testing, are also addressed and discussed. The proposed recommendations aim to improve MCP risk stratification by structuring and standardizing the histopathologic approach. The adoption of a multidisciplinary team discussion remains crucial for MCP patient management.