The paper shows a consecutive change in the classifications of lymphoid tissue tumors in the context of the development of immunology and molecular genetics. It describes innovations in the revised 2008 WHO classification. The immunophenotypes and molecular genetic changes of the most common lymphoid tissue tumors are given. Two hundred and forty-three patients with non-Hodgkin’s lymphomas have been examined using cytofluorimetric and cytological methods. The accuracy of diagnosis of lymphomas was 98%; the immunophenotype was established in 90% of the cases.