A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz, Kelli A. Stacy, ELS. Previously reviewed by Rita Nanda, MD, Department of Medicine, Section of Hematology/Oncology, University of Chicago Medical Center, Chicago, IL. Review provided by VeriMed Healthcare Network (9/11/2006).