Histologic Evaluation of Malignant Polyps and Low-Stage Colorectal Carcinoma

Abstract

Context.— With widespread screening for colorectal cancer, the number of early-stage colorectal cancers is increasing. Local excision of pT1 tumors is associated with considerably less morbidity and mortality, but this must be weighed against risk of lymph node metastases. Objective.— To understand histologic prognostic factors associated with adverse outcome in malignant polyps. Data Sources.— Pertinent literature regarding histologic features of prognostic significance in malignant polyps and low-stage colorectal carcinomas is summarized and our institute's cases are used to highlight these histologic features. Conclusions.— Poor prognostic factors for malignant polyps include high tumor grade, presence of lymphovascular invasion, tumor less than 1 mm from resection margin, submucosal invasion deeper than 1 mm, and high tumor budding. These features should be assessed by the pathologist and communicated to the clinical team in order to allow proper management.