A Primary Retroperitoneal Diffuse Large B-Cell Lymphoma: A Challenging Diagnosis.

Although quite rare, retroperitoneum can harbour malignant limphomas. On the grounds that the anatomical location is uncommon and the symptoms are scarce, the diagnosis is usually late and challenging. Imaging methods such as magnetic resonance imaging, computed tomography (CT) and positron emission tomography-computed tomography (PET-CT), can characterize and locate the tumor while endoscopic ultrasound fine needle aspiration (EUS-FNA) may provide pathological confirmation. We present the clinical case of a fifty-five-year-old female that is admitted to our hospital with epigastric discomfort, nausea and vomiting. CT showed a homogenously enhancing mass lesion that encased the pancreas, in contact with the portal vein, inferior vena cava, invading splenomesenteric confluence. To investigate further, EUS-FNA was decided and it revealed lymphocyte proliferation suggestive for the diagnosis of lymphoma. Hereinafter, surgical intervention was performed and immunohistochemical analysis and sub classification of lymphoma was obtained. The final diagnosis was non-Hodgkin lymphoma, Diffuse Large B-Cell Lymphoma (DLBCL). Poly-chemotherapy with R-CHOP was initiated. At the end of the treatment fluorodeoxyglucose positron emission tomography (FDG-PET) was performed and no pathological findings were found. A brief review of literature is also provided.