Epstein-Barr Virus-Positive Not Otherwise Specified (EBV+ NOS) Lymphoma Presentation of Primary Bone Tumor Underlying a Pathological Fracture.

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma (NHL) and accounts for approximately 25% of all NHLs in developed countries. The patients usually present with constitutional symptoms and rapidly enlarging lymphadenopathy and symptomatic mass typically located in the neck or abdomen, along with an aggressive disease course. Most of the patients present with advanced disease with 60% presenting with stage 3 or 4, and those who present with extranodal involvement are usually seen at an earlier stage. Different conditions are associated with non-Hodgkin's lymphoma ranging from hereditary immunodeficiency disorders, autoimmune disorders, infections such as HIV, Epstein-Barr virus (EBV), hepatitis C virus (HCV), , and drugs such as immunosuppressants and chemotherapeutic agents. Epstein-Barr virus (EBV) is the main etiology of DLBCLs with an identified cause and it accounts for 10% of all DLBCLs.  We report a case of a 51-year-old woman who came with a non-traumatic left femur fracture and was subsequently found to have EBV-positive DLBCL. Lymphoma commonly presents as a lymph node swelling and it's uncommon to present as primary bone disease.