A RARE PRESENTATION OF DIFFUSE LARGE B-CELL LYMPHOMA AS SEVERE ACUTE HEPATITIS AND SECONDARY HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS IN A YOUNG ADULT: A CASE REPORT.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening hyperinflammatory syndrome characterized by dysregulated immune activation and cytokine storm, frequently triggered by infections, autoimmune disorders, and malignancies. Among adults, lymphoma-associated HLH represents one of the most aggressive subtypes and carries significant mortality if not recognized early. We report the case of a 24-year-old male who initially presented with constitutional symptoms, progressive jaundice, and biochemical features suggestive of acute hepatitis. Initial evaluation focused on hepatic and autoimmune etiologies; however, progressive pancytopenia, marked hyperferritinemia (>15,000 ng/mL), hypofibrinogenemia, hypertriglyceridemia, and hepatosplenomegaly raised suspicion for HLH. Further imaging revealed diffuse lymphadenopathy and infiltrative hepatic lesions. Histopathological examination of a supraclavicular lymph node confirmed diffuse large B-cell lymphoma (DLBCL). The patient fulfilled HLH diagnostic criteria with an HScore of 200, indicating high probability of disease. Despite prompt initiation of dexamethasone and immunomodulatory therapy, the patient deteriorated rapidly, necessitating transfer to a tertiary oncology center. This case highlights the diagnostic challenge posed by hepatic-predominant HLH and emphasizes the importance of considering HLH in patients presenting with unexplained hepatitis, cytopenias, and hyperferritinemia.