A rare case of EBV-positive gray zone lymphoma

Abstract

Abstract Introduction/Objective Gray zone lymphoma (GZL) is a rare and novel category of lymphoid neoplasms, first described in 2005. It is derived from B-cells and exhibits characteristics that fall between diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma(cHL). Its association with EBV is extremely rare. Here we present one such case Methods/Case Report 80-year-old female presented with progressive neck swelling and significant weight loss for over a month. It was not associated with fever, pain, or night sweats. Her past medical history was significant for hypertension, cerebrovascular accident, breast carcinoma status post-mastectomy, and non-specific B-cell lymphoma on complete remission for 9 years (post rituximab therapy). Complete blood count and metabolic profile were within normal limits. A PET scan revealed hypermetabolic cervical, supraclavicular, right axillary, and mediastinal lymph nodes, suspicious for lymphoma recurrence. The patient underwent an excisional biopsy of the left cervical lymph node which on microscopy showed lymphoid tissue in a nodular pattern with fibrosis and large areas of necrosis. The well-preserved areas showed lymphohistiocytic proliferation composed of large atypical lymphoid cells with prominent nucleoli. An area with increased eosinophils was also noted. Immunohistochemical staining showed strong positivity for EBER, CD30, MUM1, and OCT2 with dim PAX5 positivity. The cells were negative for CD20 and BOB1. Cytogenetics and molecular studies did not reveal any rearrangements or mutations. Flow cytometric study was inconclusive due to insufficient cells. A diagnosis of EBV-positive GZL was rendered. She has received brentuximab and her symptoms are improving with regressing lymph node size. Results (if a Case Study enter NA) NA Conclusion The presence of EBV positivity in GZL further complicates the diagnostic process, as it adds another layer of complexity in determining the appropriate classification and treatment. Our case highlights the importance of comprehensive morphologic phenotypic and cytogenetic investigation to diagnose GZL.