Algorithm for Paraffin-Based Subclassification of B-Cell Lymphoproliferative Disorders in Bone Marrow
Megan O Nakashima, Douglas W Warden, Sarah L Ondrejka, Jeffrey Lin, Lisa Durkin, Juraj Bodo, Eric D Hsi. Cleveland Clinic, Cleveland, OH
Background: We previously demonstrated the utility of pERK and LEF-1 immunohistochemical (IHC) stains in bone marrow biopsies (BMBs) for diagnosing hairy cell (HCL) and chronic lymphocytic leukemia (CLL) respectively. We used these with BCL-6, CD10 and Cyclin D1 IHC and MYD88 L265P mutation testing to determine diagnostic sensitivity (sens) and specificity (spec) of this non-flow-cytometry-based panel for subclassifying small B-cell lymphoproliferative disorders (LPD) in BMBs.
Design: Consecutive CLL, HCL, lymphoplasmacytic lymphoma (LPL), follicular lymphoma (FL), marginal zone lymphoma (MZL), mantle cell lymphoma (MCL), monoclonal B-cell lymphocytosis (MBL) and B-cell LPD not otherwise specified (B-NOS) cases with adequate tissue were selected with additional HCL cases (total n=71). We performed LEF-1, Cyclin D1, BCL-6, CD10 and pERK/CD20 IHC on decalcified formalin- or B5-fixed paraffin-embedded BMBs (staining thresholds pERK>70%, LEF-1>70%, Cyclin D1>20%, BCL-6>10%, CD10>50%). Allele-specific PCR for MYD88 L265P was performed on DNA extracted from formalin-FPE tissue when available (n=49).
Results: Results are summarized in table 1. LEF-1 was 100% sens and 100% spec for CLL. pERK was 100% sens for HCL and positive in one case of "atypical" CLL (aCLL; 98% spec). Cyclin D1 was 100% sens for MCL and 87% for HCL. BCL-6 sens and spec for FL was 57% and 97% respectively; CD10 was more sensitive for FL (sens 86%, spec 95%). BCL-6 was positive in one case of HCL variant (HCLv). MYD88 mutation analysis was 100% sens and 95% spec for LPL.
|# positive (%)|
|Dx (n)||pERK||LEF-1||Cyclin D1||CD10||BCL-6||MYD88*|
|CLL (12)||0||12 (100)||0||0||0||0|
|HCL (15)||15 (100)||0||13 (87)||2 (13)||0||0|
|FL (7)||0||0||0||6 (86)||4 (57)||0|
|MCL (9)||0||0||9 (100)||0||0||0|
|LPL (7)||0||0||0||0||0||5 (100)|
|MZL (13)||0||0||0||0||1 (8)||1 (8)|
|MBL (3)||0||0||0||1 (33)||0||0|
|aCLL (2)||1 (50)||0||0||0||0||0|
|HCLv (2)||0||0||0||0||1 (50)||0|
|B-NOS (1)||0||0||0||0||0||1 (100)|