IgD plasmablastic myeloma: a case report with emphasis on the cytological features.

Multiple myeloma (MM) is predominantly composed of well-differentiated neoplastic plasma cells morphologically resemble non-neoplastic plasma cells. However, some rare cytological variants of MM, such as polymorphous, pleomorphic, plasmablastic, signet-ring cell, smallcell, histiocytoid cell, clear cell, and spindle cell variants, have been reported [1]. Plasmablastic myeloma is characterized by the presence of large-sized neoplastic plasma cells containing large hyperchromatic nuclei, single or multiple prominent centrally-located nucleoli, moderate rim of basophilic cytoplasm, high nuclear/cytoplasmic ratio, faint perinuclear hof, and increased number of mitoses [1, 2]. This variant accounts for approximately 10% of all MM and shows an aggressive clinical course [3].