The composite lymphoma (CL) is defined by the presence in the same tissue or organ of two distinct histological aspects of non-Hodgkin's lymphoma (NHL), or NHL and Hodgkin's lymphoma (HL). The definition of the CL has evolved, requesting the identification of the immunophenotypic pattern and clonal distinct aspects for the two-lymphoproliferative lesions. We present a case of a 73-year-old farmer who presented with B-symptoms and multiple adenomegaly. The biopsy of a left cervical lymph node reveal a CL: a histological and immunophenotypic aspect of HL-mixed cellularity (CD15+, CD30+, CD20-) and a diffuse small cell infiltrate which meet the criteria for B-CLL (CD20+, CD23+, and CD5+). The lymphocytes in peripheral blood over 15 000/mm(3) and marrow infiltrate with small lymphocytes also sustain the B-CLL diagnosis. The relationship between the two lymphoproliferations is discussed reported to the case above, but also considering the literature data. In most of the cases the two proliferative processes are clonal related which means they have a commune lymphoid progenitor, pre-GC or early-GC with individual detachment and transit through GC (also, the afferent related processes). It is also possible that the two proliferations, which form the composite lesion to have different cellular origins, possibility sustained by the analysis of the IgH rearrangements and of the somatic mutations identified in the two clones. The EBV-role in HL-pathogeny is related to the way of salvage or/and initiation of a clonal process in a GC-cell which has major deletions in the variable part of IgH.