How to evaluate for plasmablastic lymphoma through a bone marrow biopsy?

From the Research

Evaluating for plasmablastic lymphoma through a bone marrow biopsy requires a comprehensive approach combining morphologic examination, immunophenotyping, and molecular studies, with a focus on CD138, MUM1, and MYC rearrangements, as highlighted in the most recent study 1. To evaluate for plasmablastic lymphoma (PBL) through a bone marrow biopsy, the following steps should be taken:

• Collect bone marrow samples from the posterior iliac crest using a specialized bone marrow biopsy needle, with both aspirate and core biopsy specimens obtained.
• Examine the specimens for large immunoblast-like cells with prominent nucleoli and abundant basophilic cytoplasm, which are characteristic of PBL.
• Perform immunohistochemical staining, including CD138, CD38, MUM1, and CD79a, which are typically positive in PBL, while CD20 and CD45 are often negative, as noted in 2 and 1.
• Test for Epstein-Barr virus (EBV) using EBER in-situ hybridization, as many PBL cases are EBV-positive, and consider the importance of MYC rearrangements, which occur in approximately 50% of PBL cases, as discussed in 1.
• Use flow cytometry to assess plasma cell markers and clonality, and consider cytogenetic analysis and FISH studies to detect MYC rearrangements.
• Correlate bone marrow findings with clinical information, as PBL often presents in immunocompromised patients, particularly those with HIV infection, and if PBL is confirmed, staging procedures including PET-CT scans should follow to determine disease extent, as emphasized in 2 and 1. Key considerations include:
• The importance of a thorough diagnostic workup, including immunohistochemical staining and molecular studies, to avoid misclassification of PBL, as highlighted in 1.
• The need to consider clinical information, such as immunocompromised status, in the evaluation of PBL, as noted in 2 and 1.
• The potential for CD138-negative PBL, which can be diagnostically challenging, and the use of alternative markers, such as MUM1 and OCT2, to establish the diagnosis, as discussed in 1.