Diffuse Large B-Cell Lymphoma Presenting as Pancreatic and Mediastinal Masses in a Young Female: A Diagnostic Challenge

Abstract

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL), which usually manifests as nodal involvement. However, secondary pancreatic involvement is rare, occurs in only 0.2%–2% of NHL cases. DLBCL can develop in the lymph nodes or in “extranodal sites” (areas outside the lymph nodes) such as the gastrointestinal tract, testes, thyroid, skin, breast, bone, brain, or essentially any organ of the body. It may be localized (in one spot) or generalized (spread throughout the body). Despite being an aggressive lymphoma, DLBCL is considered potentially curable. We report the case of an 18-year-old female with no prior significant medical history admitted for a 15-day history of progressive jaundice without abdominal pain, associated with retrosternal chest pain and left shoulder pain evolving over a month, in a context of a general physical decline. Physical examination revealed a generalized jaundice, no enlarged superficial lymph nodes or abdominal masses. Cardiopulmonary examinations were unremarkable. Liver function tests were abnormal, with a normal lipase. A contrast-enhanced thoraco-abdomino-pelvic CT scan revealed multiple, irregular, hypodense and locally advanced masses in the pancreatic head and isthmus (largest 27.7 × 19 mm), with significant biliary tree dilatation. Additional findings included splenic nodules and a mediastinal-pulmonary mass extending 60 mm vertically. Endoscopic ultrasound (EUS) with fine-needle biopsy detected two hypoechoic pancreatic lesions (19 × 27.7 mm) and two nodular splenic lesions (13 × 16 mm and 8 × 11 mm), suspicious for lymphomatous involvement. Histopathological examination revealed a proliferation of large atypical lymphoid cells. Immunohistochemistry confirmed a B-cell lymphoma, with strong CD20 and BCL6 expression, Ki-67 >95%, and absence of CD10, BCL2, and TdT. Scattered reactive T-cells were also noted. The patient started intensive chemotherapy with a good clinical improvement. Although rare, secondary pancreatic involvement in DLBCL should be considered when evaluating pancreatic masses, especially in young patients. The study points out the importance of considering lymphomatous disease in the differential diagnosis of pancreatic masses and bring out the diagnostic value of endoscopic ultrasound-guided biopsy in establishing a timely and accurate diagnosis.