PMC2823683_01
Plasma cell myeloma with intracytoplasmic and extracellular rhomboid crystalline inclusions. (a and b) Bone marrow aspirate stained with Wright-Giemsa. Note abundant rhomboid crystals present in the extracellular space (a; arrows) and intracytoplasmic in plasma cells (b; arrow-heads). (c) H&E stain of bone marrow biopsy section showing prominent rhomboid crystals (arrow). (d) Immunohistochemistry for lambda-chain highlights monotypic plasma cells with positive stain of the extracellular crystals (arrow). Bar 200 mum (a), 20 mum (b), and 50 mum (c and d).
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F1
Scattered free extracellular rhomboid shaped crystals were also noted (Figure 1a, 1b and 1c). The crystals were weakly Ig lambda positive (Figure 1d).