A retrospective analysis of the clinical results in relation to the Rappaport histological classification

The Rappaport classification of the non-Hodgkin's lymphomata was applied to 460 cases at the Princess Margaret Hospital. Statistically significant differences in the numerical incidence between the nodular and diffuse patterns was found for the entire series and for the lymphocytic, "histiocytic" and mixed cell types individually. All of the undifferentiated types were diffuse. These differences were sustained for the degrees of differentiation within the lymphocytic group. The "histiocytic" group was not subclassified by differentiation. The cell types differed in the numerical distribution of the patterns. The lymphocytics were predominantly diffuse but their nodular forms constituted a higher proportion of the nodular pattern than did their diffuse types of the diffuse group. More of the well differentiated lymphocytics were nodular than were diffuse and they formed a higher proportion of the nodular group than they did of the diffuse. On the other hand, the poorly differentiated lymphocytics were predominantly diffuse and these were less well represented in the nodular group than in the diffuse tumours. The intermediate differentiated types were usually diffuse but slightly better represented in the nodular group. Most tumours of the "histiocytic" type were diffuse and these constituted a higher proportion of diffuse than the nodular tumours. The mixed cell lesions were predominantly nodular and comprised a much higher proportion of nodular lesions than diffuse. No real differences were identified amongst the histological types according to age or sex distributions. The crude survival to 4 years differed significantly for the histological types. For the entire series and for each cellular type, the nodular patterns were superior to the diffuse, although, in the lymphocytic well differentiated types, pattern made no real difference to survival.