Overlap between EBV‐positive diffuse large B‐cell lymphoma, NOS, in a young patient and angioimmunoblastic T‐cell lymphoma: A diagnostic pitfall

Abstract

There may be significant histopathologic overlap between EBV-positive DLBCL, NOS, and other diagnoses including angioimmunoblastic T-cell lymphoma (AITL). Resolution of this differential diagnosis may be particularly challenging and require extensive investigation of clinicopathologic features. We report an unusual case of cervical lymphadenopathy and retroperitoneal mass in a 34-year-old male patient. This case demonstrates significant histopathologic overlap between EBV-positive diffuse large B-cell lymphoma, NOS, and AITL, which can be a diagnostic pitfall. 2 | PRESENTATION OF CASE 2.1 | Clinical history A 34-year-old man with no significant medical history presented acutely with supraclavicular lymphadenopathy, fever, night sweats, and weight loss. Laboratory studies showed increased ferritin (9006 ng/mL) and lactate dehydrogenase (700 U/L), mildly increased aminotransferases levels (79 U/L), and pancytopenia (WBC 2.0 × 10 3 /µL, hemoglobin 7.6 g/dL, platelet count 32 × 10 3 /µL). Epstein-Barr virus PCR detected 608 515 copies per mL in whole blood. Serum immunoglobulin levels were in normal range except for decreased IgM (15.75 mg/dL). Direct antiglobulin test was positive for both IgG and complement, and warm autoantibody was detected. Computed tomography scan showed bilateral cervical lymphadenopathy extending to the anterior mediastinum and a retroperitoneal mass, as well as splenomegaly (Figure 1). 2.2 | Histopathological analysis Histologic sections of cervical lymph node excisional biopsy showed near total nodal effacement by a hematolymphoid infiltrate causing marked paracortical expansion (Figure 2). The infiltrate was polymorphic and included scattered large atypical lymphocytes on a prominent background of