malignant b cell lymphomas vs benign lymphoproliferations and the role of immunoglobulin heavy chain gene rearrangement analysis

abstract  background and objectives malignant lymphoma may be very difficult to be diagnosed through routine histopathological methods because they may mimic reactive architecture or contain reactive infiltrates. detection of the monoclonal lymphocyte population is one of the best methods of diagnosis since a monoclonal proliferation is strongly suggestive of neoplasia. by means of a pcr method it is possible to detect the immunoglobulin heavy chain (igh) gene rearrangement and consequently the lymphocyte clonality.  materials and methods we evaluated formalin-fixed, paraffin-embedded biopsies, and bone marrow aspiration of 12 cases with non definite or suspicious histopathological diagnosis of non hodgkin b cell lymphoma. after dna extraction and quality control, semi-nested pcr was performed using consensus primers for amplification of cdr-3 region. pcr products were analyzed after heteroduplex analysis using polyacrylamide gel electrophoresis and silver staining.  results 75% and 16.6% of patients showed clonal and polyclonal patterns respectively. one case showed weak monoclonal band in smear background and remained suspicious after duplicate pcr.  conclusions our findings are comparable with other international studies and support the concept that molecular techniques such as pcr provide a helpful approach in detection of monoclonal immunoglobulin rearrangements in malignant lymphoma. this is especially true for suspicious cases, but always in combination with clinical and histopathological information.    key words : b-cell lymphoma, immunoglobulin heavy chain, gene rearrangement