Abstract: Grey zone lymphoma (GZL) is a rare subtype of B-cell lymphoma characterized by features of both classical Hodgkin lymphoma and non-Hodgkin lymphoma, often co-expressing B-cell lineage markers such as CD20 and CD19 alongside Hodgkin markers like CD15 and CD30. Clinically, GZL typically presents as a mediastinal mass associated with superior vena cava (SVC) syndrome and demonstrates relative resistance to standard chemotherapy regimens. GZL can arise from either thymic or non-thymic sources, with molecular assessments revealing overactivation of the NF-κB pathway in thymic-origin cases, while non-thymic cases exhibit defective apoptosis, primarily through mutations in TP53, BCL2, and BIRC6. Therapeutic strategies for GZL encompass anthracycline-based chemotherapy, targeted therapies like Brentuximab and Nivolumab, and salvage hematopoietic stem cell transplantation (HSCT) or radiotherapy (RT) for refractory cases. This article will delve into the clinical presentation, precise pathogenesis of GZL for our patient with combined defect in apoptotic pathway and overactivation of NF-K pathway, emphasize in the existing gaps in treatment options and the challenges faced in outpatient management.