Observer Disagreement in the Classification and Histology of Hodgkin's Disease2

Individual observers, independently evaluating the histologic aspects of the classification of Hodgkin's disease, had a level of agreement too low to be scientifically useful. Working together, however, with appropriate statistical advice and quality control, 3 observers can provide histologic data of significantly better quality for studies of this disease. In addition, the use of 3 observers increases the accuracy of classifying individual cases beyond that which could be achieved by even the most experienced observer working alone. The results of this study raise serious doubt about the validity of clinical therapeutic trials in which the diagnosis and classification of lymphoreticular neoplasms are based on single observations by pathologists of varying experience. The use of consensus findings of a panel of pathologists is recommended in the diagnosis and classification of Hodgkin's disease and in any disorder which is difficult to diagnose and to classify histologically.