CD37 and CD44 evaluation by flow cytometry: can these markers improve B cell lymphoma characterization?

Diffuse large B cell lymphoma (DLBCL) is a heterogenous entity with many prognostic ancillary tests that are based on immunohistochemistry. These include cell-of-origin determination by the Hans criteria and “double expresser” characterization. Additionally, MYC fluorescence in situ hybridization required to distinguish DLBCL from its morphologically similar counterpart, hit lymphoma” or high-grade (HGBCL), “Burkitt-like” worse prognosis than DLBCL. All such require judicious triage of oftentimes limited specimens. Loss expression CD37 has been associated outcomes Absence CD44 more commonly seen Burkitt Very few studies have evaluated flow cytometric analysis, which permits quantitative assessment. To evaluate utility these two markers, we retrospectively reviewed seventy-three non-Hodgkin specimens was cytometry. Median intensity ratio (MFIR) calculated dividing median population background non-B mononuclear cells. In lymphomas DLBCL-like morphology, loss rearrangement (MFIR rearranged 0.3082 vs intact 1.09, p=0.003). also germinal center cell-like (GCB) GCB 0.4139 non-GCB 1.499, p=0.036) as other studies. DLBCL, not cell-of-origin, double expresser status, rearrangement. While our findings confirmation larger case series, decreased cytometry an otherwise biopsy features may provide impetus for FISH testing ultimate classification.