Polymerase chain reaction in the diagnosis of T-cell lymphoma in paraffin-embedded bone marrow biopsies: a comparative study

Aims: In routine histological analysis of bone marrow biopsies, the distinc tion between reactive T-cell infiltrates and T-cell lymphoma can be difficu lt, even with the use of extensive immunohistochemistry. The aim of this st udy was to evaluate the diagnostic contribution of TCR-gamma gene rearrange ment analysed by PCR. Methods and results: The samples studied consisted of 46 paraffin-embedded bone marrow biopsies (diagnosis, staging and follow-up) from 26 patients wi th T-cell lymphoma, The bone marrow biopsies were categorized into three gr oups according to the morphological and immunohistochemical results, Group 1, positive for T-cell lymphoma (24 bone marrow biopsies), group 2, suspici on of T-cell lymphoma (15 bone marrow biopsies) and group 3, negative for T -cell lymphoma (seven bone marrow biopsies). DNA could be amplified in 45/4 6 bone marrow biopsies (98%), Clonal rearrangement was detected in 30/45 bo ne marrow biopsies tested (67%) including 15/24 bone marrow biopsies (62.5% ) of group 1, 11/14 (78.5%) of group 2 and 4/7 (57%) of group 3. In total, PCR analysis supported a diagnosis of T-cell lymphoma in 15/45 bone marrow biopsies (33%), in which histological and/or immunohistochemical examinatio n provided inconclusive evidence of malignancy. Conclusions: TCR-gamma PCR is a complementary tool for the assessment of T- cell lymphoma in bone marrow biopsies. Optimal evaluation of bone marrow bi opsies requires an integrative approach of all available results from morph ology, immunohistochemistry molecular biology and clinical data.