Severe pancytopenia as presenting feature in newly diagnosed multiple myeloma (NDMM): a rare presentation.

C. De Vriendt, S. Kennes, M. Hofmans, P. Vlummens

Objectives
To broaden our insights into the clinical spectrum of NDMM through presentation of an intriguing patient, presenting as acute leukemia.

Methods
We identified a patient who presented with severe pancytopenia and febrile neutropenia as the only sign of NDMM. As this was an extremely atypical presentation, we performed a retrospective analysis of all NDMM patients seen at our center between 01/01/2009 and 31/07/2017 to identify additional cases. All 172 patients met the IMWG diagnostic criteria for MM.

Results
A 66-year-old female was referred because of febrile neutropenia. She had developed progressive dyspnea over the last few weeks and spiking fever since 96 hours. Laboratory work-up showed severe pancytopenia with Hg 4 g/dL, WBC 600/µL and thrombocytes 27000/µL. No peripheral blasts/plasmacells were seen. Due to the acute onset and severity of the cytopenia, an acute leukemia with concomitant infection was suspected. Subsequent bone marrow biopsy surprisingly revealed the presence of atypical plasmacells (>60%, CD138+/kappa+). Serum protein electrophoresis displayed the presence of an IgG M-component of 31.4 g/L with skewing of the FLC-ratio. As such, the diagnosis of NDMM was made. Cytogenetic analysis showed no aberrations.

Retrospective analysis of our patient cohort confirmed the rarity of this presentation as no other patients had pancytopenia as initial key feature. Also, no one had ever presented with grade III/IV thrombocytopenia/neutropenia, respectively. Although 2 additional patients (N=3/173, 3.4%) had a Hg < 7 g/dL at time of diagnosis, none had such a marked pancytopenia as seen in this patient (N=1/173, 0.5%).

Conclusion
Albeit rare, pancytopenia can be the presenting feature of NDMM as seen in our patient. Its presence therefore doesn’t exclude the possibility of MM.