PB2114 NEUTROPHILIC LEUKEMOID REACTION ASSOCIATED WITH SMOLDERING MULTIPLE MYELOMA

Abstract

Background:Chronic neutrophilic leukemia is a rare chronic myeloproliferative neoplasm characterized by splenomegaly, sustained neutrophilia, elevated B12 levels, and negative BCR/ABL translocation. It can be confused with leukemoid reactions in the context of plasma cell neoplasms.Aims:To describe the clinical case of a female patient with neutrophilic leukemoid reaction in the context of latent IgA multiple myeloma treated at the National Cancer Institute of Colombia.MethodsClinical case reportResults:We present a 67‐year‐old woman with a history of type 2 diabetes mellitus and rosacea with headache, epistaxis, fatigue, intermittent chest pain, hyperleukocytosis in the hemograma and qualitative negative PCR BCR ABL in peripheral blood. She received treatment with hydroxyurea since January 2016 extra institutionally. Upon admission to our institution a complete bone marrow study was requested confirming the BCR ABL negativity by cytogenetics and JAK2 V617F negative mutational state, however the myelogram showed infiltration by plasma cell disorder with dohle bodies and moderate megaloblastic changes in the myeloid and erythroid series. Bone marrow biopsy was hypercellular with 30% infiltration by abnormal plasma cells. The immunophenotype of the plasmacytic population in flow cytometry revealed a positive population for CD38/CD138/CD56/B2‐m and negative CD19/CD45 with lambda restriction. Protein electrophoresis showed a monoclonal peak in the beta region, immunofixation was positive for lambda IgA, high IgA levels with a value of 3874 mg/dL. No monoclonal component was detected in the urine, including immunofixation. The free light chains in serum showed a monoclonal lambda of 116.52 mg/L, Kappa 11.01 mg/L with a ratio of 10.5. No CRAB component was shown including PET CT without bone or extramedullary lesions. Despite treatment with hydroxyurea, hyperleukocytosis persisted with 47330 cels/ul with neutrophilia (44060/uL). Finally, smoldering IgA lambda high risk multiple myeloma diagnosis was made. She started treatment with lenalidomide and dexamethasone attaining partial response after two cycles and progresive resolution of leukemoid reaction.Summary/Conclusion:The neutrophilic leukemoid reaction or a similar clinical picture should alert to the existence of a plasma cell neoplasm. The associated morphological characteristics are usually the toxic granulations and Dohle bodies like in our patient. It is not clear if neutrophilia becomes a factor of poor prognosis in smoldering multiple myeloma, for this reason the risk should be stratified according to existing guidelines. There are still controversies about the need for treatment even in higk risk patients. The fact of being IgA, having a peak greater than 3 grams in SPEP, the ratio of light chains greater than 8 were the high‐risk characteristics seen in our patient that they defined in management.image