ABSTRACT
BACKGROUND: Both chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) are CD5/19 positive. The t(11;14) MCL translocation is identified by fluorescent in situ hybridization (FISH) and can distinguish the two disorders. We attempted to identify flow cytometric and other markers predictive of a positive FISH test. METHODS: We examined 100 atypical CLL/MCL cases for demographic, hematological, and cytometric variables, 96 were FISH tested for t(11;14) and four were known MCL. RESULTS: Twenty-two cases were confirmed as MCL. Multivariate analysis identified four variables associated with MCL: thrombocytopenia (taken as Plt < 150 × 109/L), CD23 negative, CD20 strong, and CD38 positive, with these variables a four-point score was devised. By ROC analysis, the MCL score was superior in differentiating MCL to the Marsden CLL score (AUC 0.95 vs. 0.78). MCL score ≥ 2 showed sensitivity 1, specificity 0.66, positive predictive value (PPV) 0.49, and negative predictive value (NPV) 1 for MCL. The score was then prospectively validated on an independent cohort of 44 cases of atypical CLL/MCL. No MCL had a score < 3. Validation PPV/NPV of score ≥ 3 were 0.5/1. Overall survival in MCL was shorter compared to t(11;14) negative patients (median 3.3 vs. 4.2 years, HR 2.2, 95% CI 0.87-5.5, P = 0.1). CONCLUSIONS: The score described can be used to identify cases of CD5/19 positive lymphoproliferative disorders likely to be t(11;14) positive MCL.
