DLBCL belongs to the group of NH lymphomas representing the part of around 30 percent of all lymphomas. It occurs at any stage of differentiation of lymphocytes B. Concerning morphologic and prognostic characteristics it represents a heterogeneous group of diseases. By the usage of the GEP method is is possible to distinguish two main groups of lymphomas; germinative and non germinative type (belongs to ABC and group of unclassified subgroup of DLBCL). Due to the difficult applicability in daily practice GEP is replaced by IHC. Prognostic value of certain markers is established, although their importance is not uniquely proven in all studies. Such differences could be the consequence of the fact that no consensus is reached on the existence of a unique immunohistochemical method for the diagnosis. Therefore, the need for creation of a unique algorithm and unique consensus on the methods used for diagnosis is necessary. Immunohistochemical algorithms were created for easier handling with tissue material and to distinguish DLBCL subgroups as well as for higher success in determining the prognosis of patients. Primary therapy of patient is described as acronym R-CHOP and indicates therapy with cyclophosphamide, doxorubicin (Hydroxydaunorubicin), vincristine (Oncovin) prednisone and rituximab. Introduction of rituximab (anti-CD20 monoclonal antibody) has proven successful in the treatment of the patient. However, 40 percent of patients experienced relapse. Thus, research efforts to broaden the usage of markers and to explain their expression in DLBCL resulted in numerous clinical trials and search for new drugs which target certain proteins that tumor cells express on its surface. Sorting certain types of DLBCL within different prognostic groups is necessary to determine the prognosis of disease, enabling individualized and better treatment of patients.