Case 22: A 65-Year-Old-Woman With Neutropenia

A 65-year-old woman was referred to our hematology clinic for persistent, unexplained leukopenia that had been intermittently noted over several years.She denied recurrent infections, fever, weight loss, or other constitutional symptoms, though she occasionally experienced mild dizziness and fatigue.She had no significant past medical history, took no regular medications.Regarding her occupational history, she was a retired elementary school teacher, and denied any known exposure to toxins or herbal medicines.Her primary clinic had previously remarked that her white blood cell (WBC) count was "slightly low," but no further evaluation had been conducted.Her vital signs were stable on presentation.She was afebrile, with normal blood pressure, pulse, and respiratory rate.Physical examination revealed no lymphadenopathy, hepatosplenomegaly, or skin abnormalities.A complete blood count (CBC) performed two years earlier had already shown leukopenia, with a WBC count of 3.90 × 10 9 /L and an absolute neutrophil count (ANC) of 1.45 × 10 9 /L.Hemoglobin and platelets were within normal limits.At our clinic, repeat CBC again demonstrated leukopenia with WBC (3.18 × 10 9 /L) and ANC (1.12 × 10 9 /L).Red cell indices were stable, except for mild macrocytosis (mean corpuscular volume [MCV], 98.6 fL), without overt anemia.CBC results are summarized in Table 1.While reviewing potential causes of neutropenia, the patient reported that her oldest sister had recently been hospitalized elsewhere for syncope, cytopenia, and neuropathy.Her sister was found to have a markedly elevated urine arsenic level.Given this history, we performed a urine arsenic test for our patient, which revealed a significantly elevated level of 767 µg/L (reference < 150 µg/L). CLINICAL IMPRESSIONDr. Min Gon Kang: Chronic cytopenia possibly due to arsenic intoxication.Other causes such as viral, autoimmune, and nutritional etiologies should be considered in the differential diagnosis.