Synchronous Lymphoma: Diagnostic Challenges in a Case of Coexisting Diffuse Large B-cell Lymphoma and Classical Hodgkin Lymphoma.

Synchronous lymphoma (SL) is the simultaneous occurrence of two or more unique kinds of lymphomas in the same individual at the initial diagnosis. Accurate diagnosis requires histopathological examination, immunohistochemistry (IHC), and molecular studies. We found only a handful of reported cases of SLs involving different anatomical sites in medical literature, and no large-scale studies have specifically addressed the frequency of this combination. Given the rarity of this combination, each case is often reported as a unique case study, and treatment approaches may vary depending on individual circumstances. Here, we report a case of a 60-year-old female patient presenting with pain in the abdomen, vomiting, fever, significant weight loss, and palpable inguinal nodes. Her endoscopic biopsy from the stomach revealed diffuse large B-cell lymphoma (DLBCL) while the inguinal node biopsy showed classical Hodgkin lymphoma (cHL), mixed cellularity type. Our report discusses and highlights the importance of detailed clinical history, investigations, and molecular workups that are essential to diagnosing these rare cases.