Evaluation of a panel of expert pathologists: review of the diagnosis and histological classification of Hodgkin and non-Hodgkin lymphomas in a population-based cancer registry.

AbstractCorrect histological classification of malignant lymphomas is important but has always been a difficult challenge. Since 2001 the World Health Organization (WHO) classification has been used, which should make it easier to define distinct disease entities. The purpose of this study was to evaluate the usefulness of a panel of expert hematopathologists in reviewing the diagnosis of malignant lymphomas and to examine whether the discordance between primary and panel diagnoses has declined throughout the years. All patients with a primary malignant lymphoma diagnosed between 2000–2001 and 2005–2006 were identified through the population based cancer registry. All diagnoses were reviewed by a panel of three expert pathologists. In 2000–2001, 344 patients were included, and in 2005–2006, 370 patients. The overall discordance rate decreased from 14% in 2000–2001 to 9% in 2005–2006 (p = 0.06). We were able to identify lymphoma subgroups with the highest discordance rates and lowest discordance rates (man...