A Case report: Chronic Eosinophilic Leukemia

Abstract

Background: Chronic eosinophilic leukemia (CEL) is a rare, slowly progressive hematologic malignancy characterized by clonal proliferation of eosinophils in the bone marrow due to underlying genetic mutations. Persistent eosinophilia (>1.5 x 109/L) for 1–6 months is a key diagnostic criterion. The presence of the FIP1L1::PDGFRA fusion gene and increased blast or abnormal cells in the bone marrow further supports the diagnosis. Case presentation: A 63-year-old male presented with symptoms of dry skin, pruritus, skin rash, enlargement of cervical, axillary, and inguinal lymph nodes, headache, and edema. According to the medical history, the disease began 4 years earlier with pruritus in the lower legs and progressed over the past 2 years with worsening skin rash. Complete blood count revealed eosinophilia of 48.6%. Based on leukogram, myelogram, skin histopathology, and cytogenetic analysis performed in China, a diagnosis of chronic eosinophilic leukemia was established. The patient responded well to treatment with imatinib and hydroxycarbamide. Conclusion: Clinical manifestations of chronic eosinophilic leukemia are often nonspecific and may be misdiagnosed as dermatological conditions. Therefore, cytogenetic analysis (including FISH), leukogram, myelogram, and skin histopathological examination play a crucial role in accurate diagnosis.