Pleomorphic B cell neoplasm with monoclonal IgA secretion: a case report

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• Immunoglobulin A (IgA) paraproteinemia is typically associated with multiple myeloma.
• Waldenström's macroglobulinemia is characterized by IgM paraprotein production.

Observation:

• A case of non-myelomatous malignant disease presented with IgA paraproteinemia.
• Bone marrow examination revealed a pleomorphic lymphoid/plasmacytoid infiltrate.
• Immunofluorescence showed IgA in both the cytoplasm and cell surface.

Findings:

• The cellular ultrastructure shared features with myelomatosis but differed in IgA expression.
• This IgA expression pattern is distinct from typical IgA multiple myeloma.
• The case demonstrates IgA paraproteinemia can arise from diverse B cell proliferative diseases.

Implications:

• IgA paraproteinemia may occur in a wider range of B cell malignancies than previously recognized.
• This suggests a potential spectrum of disease, analogous to IgM paraproteinemia.
• Further research is needed to delineate these B cell proliferative disorders and their associated paraproteins.