HL-287: An Unusual Presentation of Discordant Classical Hodgkin and Non-Hodgkin Lymphoma in a Young Adult

Introduction Discordant lymphoma is the condition in which two subtypes of lymphoma occur synchronously in different anatomical sites. The objective is to highlight this exceptionally rare combination in order to prevent inaccurate diagnosis. Case Presentation A 20-year-old female presented with typical signs of diffuse supraclavicular and mediastinal lymph node enlargement. Based on the characteristic histological appearance of lymph nodes, she was diagnosed with classical mixed cellularity Hodgkin Lymphoma. Treatment was initiated with ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) chemotherapy. Following four cycles of therapy, the patient underwent a PET scan that revealed partial remission with persistence of mediastinal lymph nodes. Two additional cycles of ABVD were initiated, followed by a repeat PET scan that revealed new anterior and mediastinal lymph nodes with a necrotic center. Radiotherapy was done with a dose of 36 Gy in 20 fractions. Three months later following therapy, the patient underwent a PET scan that showed new onset sub-diaphragmatic lymph nodes with necrotic centers, although it showed a major decrease in the mediastinal lymph nodes previously described. A biopsy was performed on the new appearing nodes and was in favour of diffuse large B cell lymphoma, most likely of non-germinal center cell of origin, and was expressing CD30. Following this discovery, additional cycles of R-DHAP (rituximab, dexamethasone, high-dose cytarabine, and cisplatin) were administered, resulting in a significant decrease in sub-diaphragmatic lymph nodes. Conclusion Even if strict guidelines are followed, we must remain aware that several types of lymphoma can coexist simultaneously, and discordant lymphoma should be considered, especially when new lymph nodes appear despite adequate therapy, and a biopsy is always recommended. Identifying this rare entity can offer a survival benefit.