HTLV-1 infection in acute t- lymphocytic leukemia/lymphoma

Abstract

Adult T- lymphocyte leukemia/ lymphoma (ATLL), described by Uchiyama et al. in 1977, is a distinct neoplasia of peripheral T-lymphocytes caused by human T-cell lymphotropic virus type 1 (HTLV-1). The authors describe the case of a 75-year-old female patient who presented with fever, chills, and altered mental status. The peripheral blood morphology showed large atypical lymphocytes with multilobed nuclei and flow cytometry consistent with ATLL. The authors discuss the pathophysiology, differential diagnosis, and subtypes of ATLL in addition to the diagnostic approach using flow cytometry when bone marrow biopsy is not available and modalities of treatment.

Keywords: Human T-lymphotropic virus 1; Leukemia, Lymphoid; Leukemia-Lymphoma, Adult T-Cell.

Figure 1. Atypical lymphocytes in peripheral blood smear surrounded by RBC (echinocytes) with small thorny projections. (Original Magnification x1000).

Figure 2. Flow cytometry analysis on peripheral blood lymphocytes. The atypical lymphocytes were detected by blood flow cytometry, gated and painted in red color. A. shows side scatter (SS) versus forward scatter (FS); B. The atypical cells are strongly expressing CD45, C. The atypical cells are expressing CD2, but not CD7, D. The atypical cells are CD4 positive but CD8 negative, E. The majority of atypical cells are expressing CD3 and CD5. F. The atypical cells are expressing CD4 while CD25 Is partially expressed. G. The CD4 positive atypical T-cells are negative for CD7. H. The atypical cells are negative for CD56.