en Supportive and Palliative Care Case Report and Series <p style="text-align: justify;">Introduction: Primary gastric lymphoma (PGL) is a rare tumor, whose differential diagnosis may become complicated without precise immunohistochemistry (IHC) and genetic analysis.<br> Case Presentation: A 33-year-old woman presented with gastric cancer and had undergone gastrectomy without precise IHC and staging in another center. Inappropriate IHC after surgery showed diffuse large B-cell lymphoma. After her admission to our center, due to gastrointestinal (GI) symptoms further evaluations were performed, leading to application of chemotherapy and radiotherapy regimens. In the next admissions, involvement of tibia, jaw, and gingiva took place and Burkitt lymphoma was diagnosed with precise IHC panel, which made alteration in the treatment. In the last admission, she expired due to renal failure and tumor lysis syndrome.<br> Conclusions: There was some mismanagement in this case, especially incomplete and inappropriate IHC panel, which led to wrong diagnosis.</p> MYC, Burkitt Lymphoma, Tumor Lysis Syndrome, Diffuse Large B-cell Lymphoma. 32 35 http://mcijournal.com/browse.php?a_code=A-10-131-1&slc_lang=en&sid=1 Hasan Jalaeikhoo jalaeikhoo@gmail.com 10031947532846001222 10031947532846001222 No AJA Cancer Research Center (ACRC), AJA University of Medical Sciences, Tehran, Iran Mohsen Rajaeinejad mrajaei@gmail.com 10031947532846001223 10031947532846001223 No AJA Cancer Research Center (ACRC), AJA University of Medical Sciences, Tehran, Iran Manoucher Keyhani mkeyhani@hotmail.com 10031947532846001224 10031947532846001224 No Hematology and Oncology Research Center Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran Mahsa Keshavarz-Fathi mahsa.keshavarz20@gmail.com 10031947532846001225 10031947532846001225 Yes School of Medicine, Tehran University of Medical Sciences, Tehran, Iran