Bone Marrow Biopsy for the Staging of Diffuse Large B-Cell Lymphoma: Is It Necessary Bilateral Trephine Biopsy?.

In this retrospective analysis we study the usefulness of bilateral rather than unilateral iliac trephine biopsies in demonstrating Diffuse Large B-Cell Lymphoma (DLBCL) in the bone marrow (BM). A total of 28 DLBCL cases with BM infiltration were investigated with bilateral iliac trephine biopsy during staging. Our propose was to evaluate the incidence of unilateral BM involvement, and we compare the BM biopsy size with negative and positive BM infiltration. In 28 cases studied it was analyzed 70 BM fragments. These fragments were reviewed separately by pathologist about size and infiltration. In this group, 6 cases (21.4%) were unilaterally positive. The median number of fragment per case was 2.5; the median size of BM fragment was 11.01 mm (± 5.12) and BM fragment per case was 27.53mm. It was not found difference between size BM fragment in negative or positive fragments 11,57mm (±5.2) versus 10.95mm (±5.1), p>0.05, respectively. In 24 cases it was possible to compare negative and positive BM infiltration with age, sex, LDH and computerized tomography (CT) staging. In addition, it was not found difference between unilateral and bilateral BM infiltration about LDH and age, and CT. (Table 1). Conclusion: Although in unilateral infiltration cases did not change risk factor in International Prognostic Index (stage III–IV) by CT, we conclude that bilateral trephine biopsy is superior to unilateral, because bilateral biopsy could increase by 21,4% the detection of BM involvement by DLBCL, without difference between the size in negative versus positive fragments. Table 1. Distribution of Unilateral and Bilateral Bone Marrow infiltration by categories Unilateral infiltration (%) Bilateral infiltration (%) Age < 60 21% 50% Age ≥ 60 4% 25% Sex Male 16% 29% Sex Female 8% 47% CT staging I–II - 35% CT staging III–IV 26% 39% LDH Normal 8% 34% LDH Elevated 16% 42%