MYD88 L265P Somatic Mutation: Its Usefulness in the Differential Diagnosis of Bone Marrow Involvement by B-cell Lymphoproliferative Disorders

Am J Clin Pathol. 2013 Sep;140(3):387-94. doi: 10.1309/AJCP10ZCLFZGYZIP.

Abstract

Objectives: To examine the usefulness of the MYD88 L265P somatic mutation in identifying cases of lymphoplasmacytic lymphoma (LPL) from other lymphoplasmacytic neoplasms in bone marrow biopsy specimens.

Methods: We studied 64 bone marrow biopsy specimens with involvement by various small B-cell lymphomas or plasma cell myeloma.

Results: The MYD88 L265P somatic mutation was present in 13/13 cases of LPL, 1/13 cases of hairy cell leukemia, and absent in the other mature B-cell neoplasms tested. A test set of diagnostically challenging bone marrow cases with lymphoplasmacytoid morphology (B-cell lymphoma, not otherwise specified) was selected for additional review and reclassified, without knowledge of the MYD88 L265P status. Of those 16 cases, 7 were positive for MYD88, including 4/4 cases that were reclassified as LPL during the review.

Conclusions: Although not entirely specific, MYD88 L265P is a useful adjunct for bone marrow diagnosis in separating LPL from other small B-cell lymphomas and plasma cell myeloma.

Keywords: Bone marrow; Lymphoplasmacytic lymphoma; MYD88; Marginal zone lymphoma; Waldenström macroglobulinemia.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • B-Lymphocytes / metabolism
  • B-Lymphocytes / pathology*
  • Bone Marrow / metabolism
  • Bone Marrow / pathology*
  • Diagnosis, Differential
  • Female
  • Humans
  • Lymphoma, B-Cell / diagnosis
  • Lymphoma, B-Cell / genetics
  • Lymphoma, B-Cell / metabolism
  • Lymphoproliferative Disorders / diagnosis*
  • Lymphoproliferative Disorders / genetics
  • Lymphoproliferative Disorders / metabolism
  • Male
  • Middle Aged
  • Multiple Myeloma / diagnosis
  • Multiple Myeloma / genetics
  • Multiple Myeloma / metabolism
  • Myeloid Differentiation Factor 88 / genetics*
  • Myeloid Differentiation Factor 88 / metabolism
  • Retrospective Studies
  • Waldenstrom Macroglobulinemia / diagnosis*
  • Waldenstrom Macroglobulinemia / genetics
  • Waldenstrom Macroglobulinemia / metabolism

Substances

  • MYD88 protein, human
  • Myeloid Differentiation Factor 88