A Rare Case of Grey Zone Lymphoma Successfully Treated with Brentuximab Vedotin and R-CHP Chemotherapy.

Introduction: The diagnosis of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin's lymphoma (cHL), also referred to as grey zone lymphoma (GZL), is a challenging diagnosis. There are no standardized guidelines; however, evidence strongly suggests that DLBCL-based regimens are effective in the treatment of GZL. Brentuximab vedotin (BV) is an anti-CD30 antibody drug conjugate that has established efficacy in relapsed/refractory Hodgkin and some T-cell lymphomas. There is some evidence that BV has a positive response in non-Hodgkin lymphoma (NHL) with a wide range of CD30 expressions-including GZL.

Case: We present a case of a patient initially diagnosed with cHL who underwent repeat biopsy which was revealed to be GZL. Based on PET scanning and immunohistochemical studies, she was classified as a stage IIIA CD20+/CD30+ GZL patient. Given her strong CD30 expression, she underwent 6 cycles of R-BV-CHP (rituximab, brentuximab vedotin, cyclophosphamide, doxorubicin, and prednisone) chemotherapy and achieved complete response (CR) both clinically and radiographically.

Discussion: Given the rarity of GZL, this case illustrates the immense challenges in making the diagnosis, discusses the current treatment options, and suggests that BV may be a viable therapeutic candidate in the treatment of GZL.