Background: The differential diagnosis of any clinical presentations with high fever, hepatosplenomegaly, hepatic cyst and ongoing hematological pathologies might be problematic for the clinicians in zoonotic disease endemic regions, specifically in the elderly. On the other hand, cytopenias accompanied by high fever, especially absolute neutropenia and deep thrombocytopenia
have an immediate high priority in clinical practice all over the world.
Case Report: Here, we report a fatal geriatric patient with high fever, immune mediated pancytopenia, giant hepatic cysts, splenic infarction whose the final diagnosis of the said patient is T-cell lymphoma.
Conclusions: This fatal case is a good example that intensive and accelerated medical evaluation is urgent need because diminished physiologic reserve in elderly patients. Although infection remains the most common cause of Fever of Unknown Origin (FUO) in the geriatric population, hematological malignancies are also a major concern.

Keywords: Lymphoma, T-Cell, Cysts