Advances in estimating plasma cells in bone marrow: A comprehensive method review

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Accurate plasma cell quantitation in bone marrow (BM) is essential for diagnosing plasma cell neoplasms.
• Current methods like BM aspirates, immunohistochemistry, and flow cytometry have limitations including patchy infiltration and sample dilution.
• Existing techniques yield variable results, with immunohistochemistry often showing higher plasma cell percentages than other methods.

Purpose of the Study:

• To provide a comprehensive review and comparison of methods for plasma cell estimation in bone marrow.
• To highlight the strengths and limitations of each technique.
• To guide the selection of optimal methods for accurate plasma cell estimation in clinical practice.

Main Methods:

• Review of existing literature on plasma cell quantitation methods.
• Comparison of Romanowsky-stained BM aspirates, immunohistochemistry (CD138, MUM1), flow cytometry, and radiological imaging.
• Exploration of emerging techniques including AI image analysis, dual-energy CT, radiomics, and molecular assays (qPCR, NGS).

Main Results:

• Immunohistochemically stained bone marrow biopsies consistently yield higher plasma cell percentages compared to Romanowsky-stained aspirates or flow cytometry alone.
• CD138 or MUM1 immunohistochemistry and AI image analysis show promise for accurate plasma cell identification and quantification.
• Radiological imaging and molecular techniques offer complementary diagnostic information but require further standardization.

Conclusions:

• No single gold standard method currently exists for bone marrow plasma cell quantitation.
• CD138-stained biopsies are favored for accurate estimation and are pivotal in diagnosing and monitoring multiple myeloma.
• Combining multiple methods (BM aspirate, biopsy, flow cytometry) enhances diagnostic accuracy for plasma cell neoplasms. Digital pathology is expected to advance laboratory medicine.