[Chronic myeloid leukemia presenting with marked eosinophilia]

Area of Science:

• Hematology
• Oncology

Background:

• Chronic myeloid leukemia (CML) typically presents with neutrophil-predominant leukocytosis.
• A rare subset of CML patients exhibits marked eosinophilia, mimicking other hypereosinophilic syndromes.

Observation:

• An 80-year-old female with Philadelphia chromosome-positive CML presented with fever, edema, and marked eosinophilia.
• The patient experienced CML relapse after initial responses to imatinib and nilotinib, with transient response to dasatinib, ultimately succumbing to the disease.
• At relapse, neutrophilia became more prominent than eosinophilia.

Findings:

• Review of 6 CML patients with >50% peripheral blood eosinophils revealed predominantly male patients with splenomegaly.
• Associated conditions in this subgroup included cardiac disorders, peripheral vascular disease, and pleural effusion.
• Marked eosinophilia in CML can obscure the underlying diagnosis, resembling idiopathic hypereosinophilic syndrome.

Implications:

• This CML subgroup with eosinophilia presents unique clinical and therapeutic challenges.
• Further research is needed to understand the pathogenesis and optimize treatment strategies for eosinophilic CML.
• Accurate diagnosis and management are crucial for improving outcomes in patients with this rare CML variant.