Hyperplastic polyps of the colorectum - Innocent or guilty?

Hyperplastic polyps have traditionally been regarded as nonneoplastic polyp s lacking malignant potential. The demonstration of genetic alterations wit hin these lesions indicates an underlying neoplastic cause. There is eviden ce that hyperplastic polyps are heterogeneous. Most are innocuous, but subs ets may have malignant potential. Risk factors for neoplastic progression i nclude multiple, large, and proximally located polyps. Aberrant methylation resulting in the silencing of cancer genes may be an important underlying mechanism, particularly in pathways progressing to tumors with DNA microsat ellite instability. Lesions intermediate between hyperplastic polyp and can cer include admired polyps and serrated adenomas. Currently, pathologists h ave different thresholds for diagnosing serrated adenomas, including the di stinction from large hyperplastic polyps. Reasons for over looking this pat hway in the past may include rapid tumor progression and the fact that prox imally located hyperplastic polyps may be flat and not especially numerous. Management of the serrated pathway of colorectal neoplasia may require nov el approaches to screening, early detection, and prevention.