Standard textbooks of internal medicine teach the science of diagnostic reasoning but provide few illustrations of the art of diagnostic reasoning. A case-based approach to teaching internal medicine is appealing because it could illuminate both the art and the science of diagnostic reasoning. However, this book fails to effectively accomplish that objective because it lacks clarity, consistency, and conciseness.

Lack of clarity and coordination of the different case elements blurred the messages of the case presentations. The diagnostic algorithms presented in each chapter were often complicated and confusing. Deletion of explanatory annotations from published "decision-making" algorithms obscured their instructive points. In some cases, the flow of the algorithms contradicted statements in the case discussions. Poor resolution and contrast in many radiographs and electrocardiographic tracings made it impossible to discern key diagnostic findings. Ending each case with a summary of its primary instructive points would have helped to refocus the message.

Inconsistencies in message and format were annoying and further detracted from the author's intended points. When topics were discussed in more than one case presentation, the recommendations of different authors were not always congruous. The format of case presentations varied. For example, case data was sometimes commingled with discussions. The style of references varied across subspecialty sections, and the number of references per case ranged from 3 to 59. The many misspellings and typographic errors reflected inconsistent attention to detail.

Redundant coverage of some topics added unnecessary length to the book. For example, hypercholesterolemia, hypertension, and thrombolytic therapy were each covered by different authors in at least two separate case presentations. In other cases, coverage of topics was incomplete or outdated. For example, the treatment of Mycobacterium avium complex with rifabutin or the newer macrolide antibiotics and the treatment of multiple sclerosis with interferon-ß were not mentioned. Elimination of redundant coverage might have allowed for discussions of newer diagnostic and therapeutic advances.

The book contained some excellent individual case discussions. For example, the cases reviewing acid-base disorders and the diagnostic approach to adenocarcinoma were both comprehensive and up-to-date.

Teaching the art and science of diagnostic reasoning remains a noble endeavor. This book needed more clarity, consistency, and conciseness to achieve that lofty goal.