A malignant epithelial neoplasm arises in the mucosa but has a tendency to invade locally. A benign neoplasm is often well-circumscribed, and compressed normal surrounding tissue appears to form a discrete border. This localized lesion can be resected easily, with adequate margins. Without evidence for spread outside the colon, chemotherapy is unlikely to be of benefit. The biopsy specimen shows a malignant lesion; it must be removed before it increases in size and invades locally or metastasizes. If there is no family history, familial cancer with a high risk of recurrence from multiple polyps is unlikely; local excision is adequate. Such a solitary mucosal lesion is unlikely to represent a metastasis.