High-grade B-cell lymphoma with MYC and BCL2 and-or BCL6 rearrangements, also called doublehit lymphoma, is an aggressive mature B-cell lymphoma that carries both MYC and BCL2 and/or BCL6 translocations. This can present as a diagnostic challenge since clinical characteristics, morphology and immunophenotype are not accurate indicators of underlying genetic aberrations in this type of lymphoma. We report a case of a 25-year-old male who presented with a one-year history of cough, gradually increasing abdominal girth and jaundice. Definitive diagnosis was made post-mortem with additional ancillary studies using immunohistochemistry staining and fluorescent in-situ hybridization studies.