It is well-recognised that neutrophilia can occur in plasma cell disorders, presumably due to abnormal cytokine production. Did the BM confirm a clonal plasma cell disorder? In MGUS or myeloma it is unusual to have hepatosplenomegaly, so I can understand the clinician’s concern.

Chronic neutrophilic leukaemia is most commonly associated with mutations in CSF3R, so additional molecular testing (myeloid NGS panel) would be useful to determine whether this is one disease or two. If the clinician does not have access to more detailed molecular testing, then it may be reasonable simply to see whether the neutrophilia goes away when the plasma cell disorder is treated (assuming that there is an indication for treatment).

70 year old male, having neutrophilic leucocytosis, ANC approx 20-25000/cmm along with hepatosplenomegaly for last 4 years. Bone marrow done at a different centre doesn’t show any blast, Neutrohilic abundance in BM. BCR-ABL negative , JAK V617F negative.

To find out causes of neutrophilia led us to SPEP- M Spike 3.2 gram/dl. IgA 3700mg/dl, IgM and IgG very low. The patient is also having hyperuricemia, mild KFT derangement.

Am I dealing with Plasma Cell disorder with secondary neutrophilic leucocytosis or two different entities separately?

How to proceed?