Pseudoepithelial pattern in smears prepared from fine needle aspirates of plasmacytomas

A pseudoepithelial pattern was observed in smears prepared from fine needle aspirates (FNA) from three plasmacytomas. In one case cells displayed a markedly granular, 'oncocytic' cytoplasm. Granularity of the cytoplasm was due to a large number of mitochondria as shown by electron microscopy. B-lymphocytic origin of the neoplasms was confirmed by immunocytochemistry.