This book addresses practical issues that reflect the current landscape of GI pathology practice and is organized in such a way that fits the fast-pacing daily life of practicing pathologists. It contains more than 540 questions that address difficult, prevailing and controversial issues in GI pathology that are frequently encountered in daily practice and consult service. For most questions, answers are straightforward with ample literature support. However, true diagnostic controversies and clinical dilemma cannot be easily resolved with current knowledge and available information. To such challenges, an expert approach regarding how to synthesize complicated topics and clearly communicate the thinking process is valuable to readers and can help guide clinicians making optimal treatment plans for their patients. The latter types of answers are highly enriched throughout the book. Distinct from other existing GI pathology textbooks, this book is primarily organized according to disease entities and pathological processes instead of specific organs and anatomic locations. Guided by chapter titles and listed questions, readers should be able to look up a disease or a pathological feature and find the most important and relevant diagnostic criteria and pertinent differential diagnoses.