Detection of MYD88 L265P mutations in formalin-fixed and decalcified BM biopsies from patients with lymphoplasmacytic lymphoma.
The diagnosis of bone marrow (BM) infiltration by Waldenström macroglobulinemia (WM)/lymphoplasmacytic lymphoma (LPL) poses a diagnostic challenge in hematopathology. No definitive morphology or immunophenotype is able to distinguish between infiltration of paraffin-embedded BM sections by WM/LPL and other indolent lymphomas, in particular those of the splenic marginal zone (SMZL) which may also show plasmacytic maturation. An oncogenic gain-of-function mutation (L265P) in the human MYD88 gene has been found to be present in most cases of WM/LPL, yet is absent in most other cases of B-cell chronic lymphoproliferative disorders (LPD), including SMZL. Here, we compare two newly developed diagnostic protocols for detection of this mutation in paraffin-embedded archival tissues which are particularly applicable to decalcified BM biopsies. Sanger sequencing can easily detect levels of BM infiltration above 15% by WM lymphoplasmacytic cells, while the allele-specific PCR can detect the L265P mutation in BM infiltrations below 1% of lymphoma cells. We show that these methods are easily applicable to archival BM specimens and markedly improve diagnostic accuracy of BM infiltrations by indolent B-cell lymphomas.
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany; Laboratory of Hepatic Encephalopathy and Portal Hypertension, University of Buenos Aires, Buenos Aires, Argentina.
Ianina Belén
IB
Capaldi
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany.
Annette M
AM
May
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany.
Annette
A
Schmitt-Graeff
Department of Medicine I (Hematology/Oncology), Medical Center-University of Freiburg, Freiburg, Germany.
Marie
M
Follo
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany.
Konrad
K
Aumann
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany.
Gian
G
Kayser
Laboratory of Hepatic Encephalopathy and Portal Hypertension, University of Buenos Aires, Buenos Aires, Argentina.
Juan Carlos
JC
Perazzo
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany.
Martin
M
Werner
Center for Pathology, Medical Center-University of Freiburg, Freiburg, Germany. Electronic address: paul.fisch@uniklinik-freiburg.de.
Paul
P
Fisch
D001483:Base Sequence; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D016022:Case-Control Studies; D004252:DNA Mutational Analysis / Q000379:methods*; D005557:Formaldehyde; D006801:Humans; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000473:pathology; D008969:Molecular Sequence Data; D009154:Mutation; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics*; D016612:Paraffin Embedding; D016133:Polymerase Chain Reaction / Q000379:methods; D015203:Reproducibility of Results; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics*
C507779:MYD88 protein, human; D053594:Myeloid Differentiation Factor 88; D005557:Formaldehyde
Bone marrow; Infiltration; Lymphoplasmacytic lymphoma; MYD88; Molecular diagnosis; Waldenström macroglobulinemia