A Clinical Labyrinth: Diagnosis of Hemophagocytic Lymphohistyocytosis

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a rare, non-malignant immune regulation disorder characterized by hemophagocytosis. The HLH 2004 study listed the widely accepted diagnostic model, which requires the presence of 5 out of 8 criteria (Fever; splenomegaly; cytopenia; hypertriglyceridemia or hypofibrinogenemia; hemophagocytosis, ferritin >500 mcg/L; Low/absent NK-cell activity; soluble CD25 elevation). The current management guidelines based on HLH-94 studies involve immunosuppression with weekly chemotherapy (etoposide) and glucocorticoids (dexamethasone), and intrathecal methotrexate is administered in patients with CNS involvement. CASE:A 4-month-old male patient with no known disease was admitted to our institution with a fever complaint. The physical examination and ultrasound (USG) revealed an enlarged spleen: WBC 2600, Hg 7.3, ANS 390, platelet count 26.000, ferritin 8.300, triglyceride 767, AST 48, ALT 21, total bilirubin 1.6, Na 133, and fibrinogen 70. Genetic tests were processed and intravenous immunoglobulin (IVIG) treatment was initiated with 10 mg/m2/day of Dexamethasone. The findings flared up again in the following period, and a complete treatment regimen was administered according to the HLH 2004 protocol (IVIG + Dexamethasone + Cyclosporine + Etoposide). DISCUSSION and CONCLUSION:HLH should be considered in patients with prolonged fever, cytopenia hepatosplenomegaly, and hemophagocytosis, which should be investigated by performing bone marrow aspiration first.