ABSTRACT
Introduction 720 Basic assumptions for forming a differential diagnosis 721 Consequences of the intrinsic limitations in anatomic 722
pathology Specific knowledge requirements 722 Inherent problems associated with histologic evaluation 722 Extraneous problems related to artifacts of fixation, 723
processing, cutting and staining Requirement of image imprinting 723 Cognizance and understanding of the limitations of 725
individual knowledge and experience Application of rapidly evolving new knowledge, 725
technologies and changing concepts to daily practice Imprecise clinical information 725 Histologic diagnosis as an art rather than a science 725 The cardinal skill required to initiate a differential diagnosis 725 Identification of pathologic processes is markedly facilitated 726
by identifying cells Morphologic manifestations of pathologic processes 726
and their recognition Different types of pathologic processes 727 Methods of identifying pathologic processes and 727
distinguishing them from normal
Diagnostic significance of pathologic processes that 727 form distinctive patterns
The inherent role of histology 728 Fundamental importance of morphology 729 Importance of morphology in the diagnosis of benign 730
lymphoid diseases Distinguishing benign from malignant lymphoid 730
proliferations Importance of morphologic patterns and cytologic 731
features in the WHO classification of Hodgkin and non-Hodgkin lymphomas
General considerations 731 Specific examples 732 Correlation between morphologic patterns, 733
immunohistochemistry and cytogenetics Importance of cell typing in grading and prognosis 733
of lymphomas Relative merits of incisional/excisional biopsies versus 734
fine needle biopsies A summary of our systematic approach 735 Key points 736 References 736
Technology has extensively permeated all medical specialties, including diagnostic anatomic pathology, where innovative new tools are being used with increasing frequency to make accurate diagnoses and provide meaningful biologic information for prognosis and treatment.
