COLON POLYPS

Colon polyps may be single or multiple, noninherited or inherited, his tologically may vary from inflammatory, hamartomatous, neurogenic, or adenomatous, and may be benign or malignant. The various recognized sy ndromes are discussed including their clinical presentation, malignant potential, and associated tumors. Recognition of these clinical syndr omes will allow the clinician to categorize the patient and the relati ve risk. The discussion goes into the genetic studies identifying the adenomatous polyposis coli gene on chromosome 5 q21 and the identifica tion of mutations arising in the DNA repair genes (MSA2, MLH1, PMSI, a nd M52) in the HNPCC syndrome. This identified two divergent pathologi es, both involving ''multiple hits'' with mucosal cells going from nor mal to adenoma-dysplasia-carcinoma. The understanding of the multiple hit concept with the adenoma-dysplasia-carcinoma progression will aid in the further understanding of the broad neoplastic process. (C) 1997 Wiley-Liss, Inc.