Plasma cell leukemia producing monoclonal immunoglobulin E

A 78-year-old male with lumbar pain and dim consciousness presented the clinical pictures of plasma cell leukemia (PCL) producing a large amount of monoclonal immunoglobulin E (IgE)/kappa protein. Laboratory investigation demonstrated an elevated serum calcium level and renal dysfunction. Systemic bone X-ray survey disclosed only a solitary osteolytic lesion. Circulating plasma cells demonstrated CD19⁻/CD56⁻ and MPC-1⁻/CD49e⁻/CD45^+/−, the latter indicating the immature phenotype of the tumor cells. Bone marrow was occupied with immature, atypical plasma cells, of which cytoplasms were positive for IgE by direct immunofluorescence analysis. Chromosomes revealed a translocation of (11;14)(q13;q32), which is concordant with cyclinD1-protein overexpression by immunohistochemistry. He was treated with dexamethasone and vincristine, which somewhat improved the laboratory findings. He died of tumor progression after 4-month admission. The clinical and biological characteristics of IgE-producing PCL, a very rare type of plasma cell dyscrasia, are discussed, reviewing the past literature.