Malignant lymphomas in Gabon (equatorial Africa): a morphologic study of 72 cases

A retrospective morphologic analysis was conducted on 72 malignant lymphomas collected in Gabon, a country of the equatorial area in Africa. Non-Hodgkin's lymphomas (NHLs) were by far the most frequent type of lymphoma, representing 67 cases (93%); only five patients (7%) had Hodgkin's disease. Non-Hodgkin's lymphomas were classified according to two modern systems (Kiel and Working Formulation). The age distribution of NHL patients was bimodal, with the highest peak in the 0 to 14 years age group (these cases were almost exclusively associated with Burkitt's lymphomas), and with the second highest peak in the 55 to 64 years age group. The male to female ratio was 2.5:1, and the overall median age was 44 years. According to the Working Formulation, the NHL cases were composed of one follicular lymphoma (1.5%), 55 diffuse lymphomas (82%), and 11 miscellaneous lymphomas (16.5%). Burkitt's lymphoma was the most frequent NHL (17 cases; 25.4%), followed by diffuse large cell lymphoma (15 cases; 22.4%) and immunoblastic lymphoma (nine cases; 13.4%). Consequently, high-grade NHL formed the largest group (28 cases; 42%), intermediate-grade NHL formed the next largest group (21 cases; 31.3%), and low-grade NHL formed the smallest group (seven cases; 10.4%). These data are compared with series from developed and developing countries, and the observed differences in distribution of the histologic subtypes of malignant lymphoma are discussed.