Is histological investigation of polyps always necessary?

Background and Study Aims: To assess whether polyp histological type can be predicted by patient characteristics and endoscopic polyp findings. Patients and Methods: 1681 polyps in 494 patients were categorized as advan ced adenomas (villous component or severe dysplasia or early cancer) or ins ignificant polyps. Chi-squared tests were used to analyze whether polyp his tological type could be predicted based on patient age (< 60 vs, > 60 years ), gender, family history of colon polyps or cancer, presence of anemia, po lyp size (less than or equal to5 mm vs. > 10 mm), and location (left- vs. r ight-sided). Results: Insignificant polyp histology (n=1337) correlated with patient age < 60 years (P = 0.0026), lack of anemia (P < 0.0001), polyp size less than or equal to5 mm (P < 0.0001), and right-sided location (P = 0.0058). Stepw ise inclusion of these parameters demonstrated that the association of a 15 mm right-sided polyp in a patient < 60 years yielded the highest combined predictive value (96.2%) for an insignificant polyp. Conversely age 160 yea rs, presence of anemia, polyp size > 10 mm, or left-sided location, as sing le or combined parameters, demonstrated a maximum predictive value of only 75.4% for an advanced adenoma. Conclusions: A small right-sided polyp in a young patient is associated wit h a small risk (3.8%) for advanced adenomatous tissue, indicating that hist ological investigation of such a polyp might not always be necessary. Howev er, the recent recognition of flat adenomas and "mini" de novo colon carcin omas in the European population also may limit the usefulness of small poly p diameters in the exclusion of severe polyp histology.