Adult T-cell Leukemia/lymphoma Mimicking Acute Myeloid Leukemia: The First Case Report from Country with low prevalence of Human T-Lymphotropic Virus type 1

Abstract

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm associated with the human T-cell leukemia virus type 1 (HTLV-1). HTLV-1 is not endemic in the Thai population, hence the rare occurrence of ATLL. We report here the first case report of ATLL in Thailand. A case of a 76-year-old woman presented with prolonged fever for 1 month and admitted to the hospital due to acute high-grade fever, headache and generalized erythematous rashes over her body. Her complete blood count revealed leukocytosis and atypical cells with bi-to-tri lobed nuclei were frequently found on blood smear. Initially, the patient was diagnosed with acute promyelocytic leukemia based-on morphological findings and received all-trans retinoic acid. Flow cytometric analysis with acute leukemia panel showed no significant blast population. Cytogenetic analysis revealed normal female karyotype without translocation between chromosome 15 and 17. Histopathological findings with immunohistochemical results were consistent with T-cell lymphoma. Additional flow cytometry with lymphoma panel revealed the presence of a significant lymphoid subset with CD4 and CD25 expression. Confirmative serology for HTLV-1 was positive and the diagnosis of adult T-cell lymphoma/leukemia was made. Her blood cultures were positive for Cryptococcus neoformans. She was initially treated with antifungal therapy. Due to her age and overall condition, palliative chemotherapy with vincristine and dexamethasone was given, which was complicated by fatal septic shock and organ failure. Our case depicted the first ATLL case in Thailand which have not been reported before.