This protocol applies to rectal cancer arising within a rectal malignant polyp (adenoma with invasive cancer) where pathologic evaluation is complicated by a fragmented specimen, margins that cannot be assessed, or the presence of unfavorable histologic features.
Unfavorable histologic features in this setting include histologic grade 3 or 4, angiolymphatic invasion, and a positive or nonassessable margin of resection. Cases in which the excised specimen is fragmented or resection margins cannot be assessed are also included. Rectal surgery is recommended when any of these features are identified in a malignant polyp.
Management involves a surgical intervention — either a local or a more extensive abdominal procedure, selected based on individual patient and disease factors. When unfavorable pathologic features are confirmed, the more extensive abdominal approach warrants particular consideration.
Full selection criteria, procedural algorithm, and guidance are in the structured protocol below.