Related Experiment Video
Updated: Jul 11, 2026
Interphase Fluorescence in situ Hybridization of Bone Marrow Smears of Multiple Myeloma
Published on: April 15, 2022
[IgG-kappa type multiple myeloma with cytoplasmic crystalline inclusions]
Chiharu Kobayashi1, Juichi Tanabe, Mayako Aoki
1Department of Clinical Laboratory, Fujieda Municipal General Hospital.
Insights
Anemia in an 82-year-old male was linked to atypical plasma cells containing crystalline inclusions. These inclusions, identified as abnormal IgG-kappa immunoglobulin, suggest a synthesis and secretion disorder.
Area of Science:
- Hematology
- Oncology
- Immunology
Background:
- Presents a case of an 82-year-old male with severe anemia (Hb 6.9 g/dL).
- Highlights the detection of monoclonal IgG of the kappa type in serum.
Observation:
- Bone marrow examination revealed 38.9% atypical plasma cells.
- These plasma cells contained crystalline inclusions, positive for acid phosphatase, IgG-kappa, and CD138, but negative for MPO, PAS, and Congo-Red.
Findings:
- Electron microscopy characterized the inclusions as rod-shaped, rhomboid, or rectangular crystals with longitudinal striations.
- Crystals were observed within the rough-surfaced endoplasmic reticulum and surrounded by ribosomes.
Implications:
- Suggests an underlying abnormality in immunoglobulin synthesis and/or secretion.
- Contributes to understanding plasma cell disorders and the nature of crystalline inclusions.
Abstract:
An 82-year-old male was admitted to our hospital because of anemia with Hb 6.9/dl. The serum monoclonal IgG of the kappa type was detected. Bone marrow aspiration showed the presence of 38.9% atypical plasma cells with crystalline inclusions. These crystalline inclusions were stained with acid phosphatase, and remained unstained with MPO, PAS and Congo-Red staining. Immunofluorescence studies showed the plasma cells were positive for IgG-kappa type immunoglobulin and CD138. Electron microscopy revealed varying numbers of stick-like, rod-shaped, rhomboid or rectangular crystals of a variety of lengths and sizes with a periodicity giving an appearance of longitudinal striation. The inclusions were most often surrounded by ribosomes. Some crystalline inclusions were located in the rough-surfaced endoplasmic reticulum. Their presence was probably due to an abnormality in the synthesis and/or secretion of immunoglobulin.
