In the previous two volumes of this series, we presented classic problems in internal medicine as illustrated by actual cases cared for in our institution. It has been gratifying for us to see the interest that these volumes have generated with students and trainees. We remain committed to the case method of instruction, and believe that there is no better method to learn medicine than to have an individual patient problem as the basis for study of pathophysiology, natural history, diagnosis and management. We hope that our readers find this third volume as enjoyable and instructive as the editors found it. Juan M. Bowen, MD Ernest L. Mazzaferri, MD, FACP xiii Acknowledgement The editors are grateful to Jeff Smith and Jenny Riegler for their unflagging professionalism and patience. xiv Contents Case 1 Mitral Regurgitation - Chronic Versus Acute: Implications for Timing of Surgery * . * * * . . * . . . . . * . . . . . . . . . . . 1 Harisios Boudoulas, MD Charles F. Wooley, MD Advances and diagnostic imaging in a surgical technique have changed the approach to mitral valve regurgitation. This chapter provides an expert's perspective. Case 2 Cystic Fibrosis in Adults .. * ************ 36 Andrew Libertin, MD John S. Heintz, MD As children with cystic fibrosis grow into adulthood, the internist assumes a greater role in their care. Case 3 Thrombotic Thrombocytopenic Purpura . . . . . . . . . . 51 . . . Donald E. Thornton, MD Earl N. Metz, MD, FACP Patients with ITP continue to present difficulties in diagnosis and management. Two experts discuss the current approach to ITP.