Pancytopenia during tyrosine kinase inhibitor treatment – coexistence of chronic myeloid leukemia and visceral leishmaniasis: a case report

BACKGROUND Visceral leishmaniasis is a zoonosis characterized by chronic evolution of symptoms; it usually appears 2 to 4 months after the initial infection, with multiple cutaneous lesions and systemic involvement, which if left untreated results in death in 90 % of cases. CASE PRESENTATION We present a case of 29-year-old white male farmer, with chronic myeloid leukemia treated with imatinib who developed significant pancytopenia, leading to discontinuation of treatment. His neutrophil count fell to 0.5 × 10(9)/L, his platelets dropped to 85 × 10(9)/μL, and his hemoglobin was 6.4 g/dL. A bone marrow study was performed, showing complete remission of chronic myeloid leukemia and numerous Leishmania amastigotes within the macrophages. He used pentavalent antimonials replaced by amphotericin B due to acute cardiac toxicity. After 3 months, imatinib was restarted, and he again showed adequate control of the disease. The last polymerase chain reaction assessment showed a deep molecular response. CONCLUSION The hypothesis of an adverse event or secondary resistance to tyrosine kinase inhibitors, with subsequent progression to advanced disease, was initially raised, although a detailed evaluation has shown that it was an associated infectious disease.