Abstract
Isolated splenic infarcts are a rare presentation of diffuse large B-cell lymphoma (DLBCL). We report the case of a 51-year-old East Asian male who presented with pleuritic chest pain, low-grade fever, and weight loss. Imaging studies revealed progressive splenomegaly with multiple splenic infarcts, while a positron emission tomography-computed tomography (PET/CT) demonstrated hypermetabolic splenomegaly along with small lymph nodes. A lymph node biopsy confirmed DLBCL, non-germinal centre subtype with dual BCL2/CMYC expression and a high Ki67 index. He was treated with R-CHOEP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone, and etoposide), which was later switched to R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone) due to treatment-related neutropenia. End of treatment PET/CT showed persistent splenic uptake, prompting an elective splenectomy. The surgery was successful and there was no residual disease observed. This case highlights the diagnostic challenges of DLBCL presenting with isolated splenic infarction, emphasizing the role of PET/CT and biopsy in evaluation.