RT Journal Article
SR Electronic
T1 Diagnostic value of bone marrow core biopsy patterns in lymphoplasmacytic lymphoma/Waldenström macroglobulinaemia and description of its mutational profiles by targeted NGS
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP jclinpath-2019-206282
DO 10.1136/jclinpath-2019-206282
A1 Julia Garcia-Reyero
A1 Nerea Martinez Magunacelaya
A1 Sonia Gonzalez de Villambrosia
A1 Angela Gomez Mediavilla
A1 Marcela Urquieta Lam
A1 Andres Insunza
A1 Raul Tonda
A1 Sergi Beltran
A1 Marta Gut
A1 Ainara Gonzalez
A1 Santiago Montes-Moreno
YR 2020
UL http://jcp.bmj.com/content/early/2020/01/24/jclinpath-2019-206282.abstract
AB Aims The aim of this study was to describe the characteristics of the bone marrow infiltration found in a series of clinically defined lymphoplasmacytic lymphoma (LPL)/Waldenström macroglobulinaemia (WM) and IgM-monoclonal gammopathy of undetermined significance (MGUS) and to perform a targeted next-generation sequencing (NGS) for the identification of additional somatic mutations to MYD88p.L265P in LPL/WM.Methods We have reviewed a series of 35 bone marrow biopsies from 28 patients with a clinical diagnosis of LPL/WM (24 cases) or MGUS (4 cases). Bone marrow infiltration characteristics by morphology, immunohistochemistry, flow cytometry (FCM), allele-specific real-time PCR for the detection of MYD88p.L265P mutation, targeted exonic amplicon-based NGS of 35 lymphoma-related genes and direct sequencing were analysed.Results Our findings show that bone marrow trephine biopsy evaluation is superior to FCM in the identification of significant lymphoid infiltrates. A combined paratrabecular and interstitial infiltration pattern is the most common feature in LPL/WM while a patchy interstitial pattern characterises IgM-MGUS cases. MYD88p.L265P mutation was found by allele-specific-PCR in 92% of the LPL cases (22 out of 24) and 25% of IgM-MGUS cases (1 out of 4 cases). In addition to MYD88p.L265P somatic mutations in CXCR4, KMT2D, PRDM1/Blimp1, MYC and ID3 were found by NGS and direct sequencing in 4 cases.Conclusions In conclusion, bone marrow core biopsy evaluation is critical in the identification of unequivocal bone marrow infiltration by LPL/WM. In addition to MYD88p.L265P, somatic mutations in CXCR4, KMT2D, PRDM1/Blimp1, MYC and ID3 can appear in a fraction of LPL/WM.