A difficult case of angioimmunoblastic T-cell lymphoma with Epstein-Barr virus-negative large mononuclear atypical cells

[CASE REPORT] A 74-year-old man with no history of a major medical condition presented with left neck lymphadenopathy that slowly progressed over approximately 2 months. He reported no fever, night sweats, or weight loss. A physical examination revealed generalized lymph node swelling, including the bilateral neck, axillary, and inguinal lymph nodes. On laboratory examination, the complete blood count suggested mild thrombocytopenia at 14.1*104/μL. The results of a chemistry panel were normal, except for a lactate dehydrogenase level of 294 U/L, soluble interleukin-2 receptor level of 2140 U/mL, and hypergammaglobulinemia (IgG, IgA, and IgM levels were 2568, 236, and 547 mg/dL, respectively). Staging positron emission tomography/computed tomography (PET/CT) revealed hypermetabolic lymph nodes in the bilateral cervical, bilateral supraclavicular, paraaortic, and bilateral iliac regions. Moreover, hypermetabolic foci were detected in the mediastinum and spleen.