Plasma cell myeloma with t(4;14) translocation juxtaposes FGFR3 (and MMSET/NSD2) to the IgH locus. Which histological variant of myeloma is characterised by flame-red cytoplasmic inclusions representing IgA paraprotein?
- A Gaucher-like cells with fibrillary cytoplasm due to macrophage engulfment of glucocerebrosides
- B Reed-Sternberg-like cells in plasma cell myeloma with IgG secretion
- C Mott cells (morula cells) with Russell bodies and flame cell variant with IgA ✓
- D Signet-ring plasma cells with IgM secretion displacing the nucleus
Correct answer: C. Mott cells (morula cells) with Russell bodies and flame cell variant with IgA
Explanation
Flame cells (flaming myeloma cells) are plasma cells with brilliant red (flame-like) cytoplasmic inclusions due to abnormal carbohydrate side chains on IgA paraprotein, classically associated with IgA myeloma. Mott cells (or morula cells) contain multiple Russell bodies (globular Ig-filled vacuoles) and occur in both IgG and IgA myeloma but are not flame-coloured. These are visualised on Romanowsky-stained bone marrow aspirate.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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