Flow cytometry aneuploidy and cell cycle indexing as a possible tool for differentiating between CD10+ diffuse large B‐cell lymphoma and follicular lymphoma

BACKGROUND: Differential diagnosis between diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) becomes a challenge when adequate biopsy is unavailable. The present study aimed to investigate the applicability of DNA cell cycle analysis by flow cytometry (FC) for differentiating between CD10(+) DLBCL and FL. METHODS: Data were collected from 57 specimens where CD5(-) /CD10(+) /light chain restricted B cells were detected. DNA staining was performed using the Coulter DNA Prep Kit. Cell cycle fractions were evaluated by automatic analysis using the ModFit LT software. RESULTS: Histopathological analysis confirmed the diagnosis of CD10(+) FL in 30 specimens (52.6%), CD10(+) DLBCL in 24 specimens (42.1%), and CD10(+) Burkitt lymphoma in 3 specimens (5.3%). A significantly higher rate of DNA aneuploidy was detected among CD10(+) DLBCL than FL specimens (50 vs. 13.3% respectively, p = .003). Likewise, DNA index was significantly higher in CD10(+) DLBCL relative to FL (1.26 +/- 0.35 vs. 1.04 +/- 0.16 respectively, p = .004). Notably, the proportion of cells in the S-phase and proliferative fraction was significantly higher in CD10(+) DLBCL than in CD10(+) FL (S-phase: 15.97 +/- 13.94 vs. 4.43 +/- 4.41 mean +/- SD, respectively, p /=7% and proliferative fraction >/=9% were determined. These values could be used to differentiate between CD10(+) DLBCL and CD10(+) FL. CONCLUSION: Including DNA cell cycle analysis in the FC lymphoma assessment panel may be of diagnostic value in differentiating between CD10+ DLBCL and FL when adequate biopsy is unavailable.