[Lymphatic diseases specific to the tropics (Burkitt's lymphoma, tropical splenomegaly and Mediterranean lymphoma)].

Certain lymphoproliferative disorders (Burkitt's lymphoma, tropical splenomegaly, and Mediterranean lymphoma) are more frequently observed in the tropical or subtropical areas than in other parts of the world. The polymicrobial exposure of human beings in those areas to viral, bacterial and protozoal infections led to the assumption of a specific connection between these conditions and the lymphoproliferative disease. Some evidence has accumulated that the Epstein-Barr virus might be an oncogenic virus connected with the development of Burkitt's lymphoma. Repeated plasmodial infections were more tenuously thought to be associated with tropical splenomegaly and, similarly, Giardia lamblia or Vibrio cholerae infections with immunoproliferative small-intestinal disease. However, those connections are only speculative and by no means proven. Small-intestinal lymphoma represents an example of a wide spectrum of manifestations covering autonomous pre-malignant immunoproliferative stages, als well as the full-blown malignant stages. Polyclonal activation and proliferation of B-lymphocytes, as well as concomitant immunosuppression are the characteristic features of the pre-malignant situation and may be the basis for the malignant transformation of single cells. Thus, the final clinical picture resembles that of a malignant non-Hodgkin lymphoma.