The micrograph shows abundant (malignant) plasma cells with the occasional Mott cell, a plasma cell with an intracytoplasmic Russell bodies (an eosinophilic uniformly staining membrane bound body which contains immunoglobulin).

Other features of plasmacytomas (not apparent on the image) are:

• a prominent perinuclear hof (large Golgi bodies), and
• Dutcher bodies (intranuclear inclusions).

The plasma cells have the characteristic "clockface nuclei".

Multiple myeloma (which is diagnosed using several clinical criteria) is, histologically, a plasmacytoma.

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