This book provides current information for a judicious use of conventional and molecular ICC markers performed in cytologic samples to help in the cost-effective diagnosis of superficial and deep-seated masses. By providing both an eminently practical information for appropriate technical preparation of cytologic samples and a systematic exposure of the immunophenotypic and biomolecular characteristics of normal and pathological cells, the reported morphological-molecular findings highlight the characteristics of different lesions that are useful for the practical solution of a particular differential diagnosis. Chapters include description of the cytomorphology followed by a practical ICC staining pattern for each entity. Cytologic materials include serous effusions, exfoliative cytology, fine needle aspiration cytology of superficial and deep-seated masses, and squash preparation from central nervous system masses. Practical Immunocytochemistry in Diagnostic Cytology serves as a valuable resource towards understanding critical differences between tests performed on tissue samples and those carried out on cytologic samples.