Diagnostic Masquerade in Advanced Lymphoma: Angioimmunoblastic T-Cell Lymphoma Initially Mimicking Diffuse Large B-Cell Lymphoma

Abstract

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive peripheral T-cell lymphoma derived from T-follicular helper (TFH) cells and is known for significant diagnostic complexity. We report a 54-year-old male with Child-Pugh B chronic liver disease presenting with prolonged fever, generalised lymphadenopathy, weight loss, hepatosplenomegaly, ascites, and suspected marrow involvement. Initial lymph node histopathology demonstrated Epstein-Barr virus (EBV)-positive atypical large lymphoid cells with apparent B-cell predominance, strongly favouring diffuse large B-cell lymphoma (DLBCL). Additional differentials included classical Hodgkin lymphoma, peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), and EBV-associated reactive lymphoproliferative disorder. Further evaluation with bone marrow flow cytometry revealed an aberrant T-cell population expressing sCD3(dim), CD2, CD4, CD5, and CD10 with loss of CD7, establishing a TFH phenotype consistent with AITL. The final diagnosis was stage IV AITL with nodal, splenic, and marrow involvement. Treatment was challenging because of significant hepatic dysfunction and portal hypertension. The patient received carefully dose-modified cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisolone (CHOEP) chemotherapy with intensive supportive care and multidisciplinary monitoring. This case highlights the “diagnostic masquerade” of AITL, the decisive role of flow cytometry in resolving ambiguous lymphomas, and the therapeutic challenges of treating aggressive lymphoma in the setting of chronic liver disease.