The potential benefit of a noninvasive technique to distinguish benign from malignant polyps is obvious.
Strictly speaking, the term polyp refers only to benign growths; a malignant polyp is referred to as a polypoid cancer in order to avoid confusion.
One 11 mm malignant polyp was missed by optical colonoscopy and only found at reevaluation.
Hamartomatous polyps may occur anywhere in the GI tract with predominance in the small bowel (Fig. 8a and b), although most malignant degenerated polyps are detected in the stomach, duodenum and colon.
Until recently it was believed that the hyperplastic polyps do not undergo malignant transformation, but carcinomas associated with hyperplastic polyps were reported in the literature over the past few years [ 10, 11].
Three factors of invasion status (to mucosa or muscularis mucosae and not beyond), configuration, and grading of polyps were considered as indicators of malignant transformation of polyps.
While previously all hyperplastic polyps were considered to have no malignant potential [ 20], there has been a recent shift in the understanding.
In analyses limited to the 18 studies where results for adenomatous polyps were separated from all polyps (i.e., hyperplastic, malignant polyps), the meta-analysis estimate for the association between physical activity and risk of polyps was largely unchanged (RR=0.83, 95% CI: 0.73 0.93).
In addition, 10 benign mucosal polyps were stained for SMA expression to determine whether hyperplastic (but non-malignant) squamous epithelium could also induce SMA induction in adjacent fibroblasts.
But the assessment of the malignant potential of polyps is commonly performed on the basis of texture features.
