Hepatosplenic T Cell lymphoma (HSTCL) is a rare form of peripheral T cell lymphoma with an aggressive course and a poor prognosis. It affects primarily young adult males, many of them with a history of immunosuppression and autoimmune diseases. We describe a case of a 27-year-old male, previously treated with azathioprine, presenting with pancytopenia, the bone marrow was aplastic and partly infiltrated with gamma-delta T-lymphocytes (Tγδ). The diagnosis was confirmed by a liver biopsy. The patient received induction chemotherapy with a total of 3 cycles of ifosfamide, carboplatin, etoposide (ICE protocol) without ever reaching hematological regeneration, so eventually followed by allogeneic transplantation. In the 60-month surveillance, the patient still shows complete remission.