An Overview on Plasma Cell Leukemia – Behind a Disguise

Plasma cell leukemia is a rare and aggressive variant of myeloma characterized by the presence of
circulating plasma cells greater than 2x109/l in the peripheral blood. It is classified as primary if
present at diagnosis, or secondary, if evolved from relapsed or refractory multiple myeloma. It has an
aggressive clinical course with limited durations of remission and survival.
It may at times, present as a lymphoproliferative disorder, leading to misdiagnosis if proper diagnostic
tools are not used. This in turn, will lead to adoption of a completely different line of treatment.
Our patient presented with a disturbed dietary regimen and significant weight loss. He was a known
case of hypothyroidism since 2009 for which he was on medications. Before landing at our centre,
complete blood counts were done at another centre, which showed bicytopenia with
hyperleucocytosis. Bone marrow biopsy made a diagnosis of lymphoproliferative disorder while
morphologically a provisional diagnosis of Hairy cell leukemia was made.
At our center, complete blood count was repeated, which again showed similar counts with
bicytopenia and leucocytosis, but the morphological examination of his peripheral smear showed the
presence of 80% plasma cells. Immunophenotyping showed CD23(+) and CD56(+) while the
immunohistochemistry showed CD23(+), CD56(+) and CD138(+). Cytogenetics showed the presence
of t(4;14) in 5% of the cells examined. Based on the above mentioned investigations, a diagnosis of
Plasma cell leukemia was reached and the patient was placed on a treatment regimen including
Lenalidomide, Bortezumib and Dexamethasone. His blood counts reached the normal range within a
week of starting the treatment. This regimen was given for a full months and there was an overall
better response. His last follow up was a month ago and he is doing well till date.
To conclude, in the wake of constantly advancing diagnostic approaches and availability of more
precise investigative tools, one should not hesitate in employing these to reach a more accurate
diagnosis as is clinically and economically possible; so that the patient may receive the most
appropriate treatment.