[Pleural effusion in a case of non-Hodgkin's lymphoma: diagnostic use of molecular analysis].

We describe a case of advanced non-Hodgkin lymphoma which lacked palpable superficial lymph nodes and in which conventional method did not allow a conclusive diagnosis. Recognition of lymphoproliferative disease was made by analysis at the DNA level of the configuration of the immunoglobulin and T-cell receptor gene regions.