From serologic uncertainty to diagnostic clarity in unusual adult T-cell leukemia/lymphoma via HBZ in situ hybridization.

Source: PubMed, NCBI / U.S. National Library of Medicine

Adult T-cell leukemia/lymphoma (ATLL) is a rare T-cell neoplasm with geographic clustering, associated with human T-lymphotropic virus1 (HTLV-1), an oncoretrovirus. Clinical presentation is variable, and diagnosis can be challenging in atypical cases. We describe a 61-year-old man with aggressive CD4/CD8 double-positive T-cell lymphoma involving lymph nodes and bone marrow with circulating lymphoma cells. HTLV serology was positive, confirmed by western blot. However, due to the unusual presentation and absence of classic features such as hypercalcemia, skin lesions, or "flower" cells (circulating lymphoma cells with marked nuclear lobation), further confirmation was warranted. HTLV-1 bZIP factor (HBZ) in situ hybridization (ISH) was performed to confirm the diagnosis of ATLL. This case underscores the importance of including HTLV-1 serology in the initial workup of T-cell lymphomas and highlights the diagnostic value of HBZ ISH in ambiguous presentations.