This book presents rational diagnostic approaches to common areas of cytopathology, such as thyroid, lymph node and effusion cytology. It discusses differential diagnoses for each site, and describes a systematic approach to narrow down differential diagnoses in a logical manner based on cytomorphology and the judicious application of ancillary tests. Further, it introduces discriminatory panels of immunohistochemical tests, with an emphasis on patient-centred approaches with active clinicopathologic correlations. In addition, it provides practical recommendations for optimizing tissue triage for ancillary testing, in terms of both diagnostic and therapy-related testing. The book also includes sample diagnostic reports to help readers formulate appropriate comments and to aid clinicians in specific clinical scenarios, as well as test cases for readers to apply their diagnostic and specimen triage algorithms. The book equips readers to apply logical approaches tosound cytopathology reporting in daily clinical practice, guiding them through specimen collection and triage to diagnostic workup based on morphologic and clinical features, and writing rational and clinically useful diagnostic cytology reports with a focus on clinicopathologic correlation. As such it is relevant for practising cytopathologists and pathology trainees as well as for cytologists (cytotechnologists) and other clinicians involved in cytopathology diagnostic processes.