Monoclonal Gammopathy of Undetermined Significance Disguised as Chronic Neutrophilic Leukemia

Abstract

We encountered a 60-year-old woman with a medical history of diabetes mellitus, osteoporosis, peripheral vascular disease, and hypertension who had earlier presented at an outside facility with knee pain, which led to a finding of elevated neutrophil count of 35×109/L. Because she was otherwise asymptomatic but continued showing elevated neutrophil levels, she sought a second opinion at our facility. Serum protein immunoelectrophoresis with immunofixation revealed an immunoglobulin A (IgA)-κ monoclonal gammopathy concentration of 1305 mg/dL (normal 80–350 mg/dL) but relatively normal concentrations of IgG of 840 mg/dL (620–1400 mg/dL) and IgM of 36 mg/dL (45–250 mg/dL). Using clonal analysis, we found a polyclonal expression pattern in all cell types analyzed. Comprehensive work-up for multiple myeloma and infectious etiology of neutrophilia was negative. We concluded that our patient’s neutrophilia may have been due to the underlying monoclonal gammopathy. This is the first case in the literature of a patient with monoclonal gammopathy of undetermined significance presenting with chronic neutrophilia, mimicking chronic neutrophilic leukemia (CNL). Patients with CNL have a poor prognosis; therefore, it is important to distinguish diagnostically between CNL and reactive neutrophilia.

Nephrotic Syndrome Related to Chronic Neutrophilic Leukemia

“…Significant organomegaly is also unlikely to occur in myelodysplastic syndrome. There have been reports of raised neutrophil counts in association with plasma cell dyscrasias, such as monoclonal gammopathy of unknown significance or multiple myeloma (6)(7)(8). However, there was no evidence of paraproteinemia in our patient.…”

Myeloproliferative Syndromes and Thrombocythemia

“…The exact cause of CNL is not known so far. Interestingly, several reports illustrate the association of CNL with monoclonal gammopathies/ monoclonal gammopathy of uncertain significance (MGUS) and with plasmacytic proliferative disorders, including myeloma, which may even precede the onset of overt CNL (Tursz et al 1974;Vorobiof et al 1978;Watanabe et al 1984;Zoumbos et al 1987;Rovira et al 1990;Standen et al 1990;Masini et al 1992;Cehreli et al 1994;Ito et al 1996;Tanaka et al 1998;Nitta et al 1999;Dincol et al 2002;Hartley et al 2010). An association with myeloma has also been noted for other types of leukemia and related disorders, such as myelomonocytic leukemia (Raz and Polliack 1984;Akashi et al 1991), acute monocytic leukemia (Luca and Almanaseer 2003), myelodysplastic syndrome (Sato et al 1992), and erythroleukemia (Barcos et al 1979).…”