Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome characterized by uncontrolled immune activation, often associated with malignancy in adults. Early recognition and prompt initiation of treatment are crucial in managing this condition due to its rapid progression and poor prognosis. We report the case of a 75-year-old male with suspected lymphoproliferative disease who presented with clinical criteria compatible with HLH. Immediate treatment with dexamethasone led to rapid clinical improvement, and the patient was referred to hematology for continued management of the underlying disease. This case highlights the importance of constant clinical surveillance, early intervention, and the use of well-structured diagnostic tools in managing this syndrome in adults, where significant diagnostic and treatment challenges remain.