Distribution and incidence rates of lymphoid neoplasms according to the REAL classification in a single institution. A prospective study of 940 cases.

Recently, a new classification system for lymphoid neoplasms, known as the REAL classification, has been proposed. Our aim is to know the distribution of lymphoid neoplasms according to this schema and compare it with the Updated Kiel classification. We also estimate incidence rates of lymphoid neoplasms in our area. From January 1993 to November 1996, 940 patients were diagnosed of lymphoid neoplasm in our center. Histologic material was prospectively classified according to both the REAL and the Updated Kiel classifications. According to the REAL classification, distribution of all cases of lymphoid neoplasms was as follows: 73.6% B-cell neoplasm, 9.4% T-cell neoplasms, 9.6% Hodgkin's disease and 7.4% unclassifiable. Considering only non-Hodgkin's lymphomas (NHL), 87.2% of cases could be categorized according to the REAL and 77.7% with the Updated Kiel classification. These figures differed due to unrecognized categories in the Kiel schema. Annual incidence rate per 100,000 inhabitants was 20.1 for lymphoid neoplasms, and NHL alone was 9.0. In conclusion, the REAL classification allowed us to categorize more cases of NHL than did the Updated Kiel classification, fundamentally because of the inclusion of some recently described entities.