T Cell Histiocyte Rich Large B Cell LymphomaPresenting as Hemophagocytic Lymphohistiocytosis:An Uncommon Presentation of a Rare Disease

T cell histiocyte rich large B cell lymphoma (THRLBCL) is a rare subtype of non-Hodgkin’s lymphoma characterized by malignant Bcells with reactive T lymphocytes. The pathophysiology is thoughtto involve cytokine-mediated evasion of T cell immune responseby malignant B cells. It usually presents at an advanced stage with extranodal involvement. An extremely unusual manifestationof the disease is hemophagocytic lymphohistiocytosis (HLH) which is a hyperinflammatory disorder. We present a case of a43-year-old male who presented with recurrent fever and recent radiologic imaging showing splenomegaly and right inguinallymphadenopathy. On presentation, he had a fever of 105∘F. Laboratory work-up was consistent with pancytopenia, elevated lactatedehydrogenase, elevated D-dimer, and a ferritin of 24,247 ng/mL. The patient was started on steroid therapy. An excisional biopsyof the right inguinal lymph node was consistent with a diagnosis of THRLBCL and the patient subsequently received six cycles ofchemotherapy with R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone) after which a PET-CTscan showed no evidence of biologically active disease and ferritin was down to 822 ng/mL. We discuss the clinical manifestationsand diagnostic and therapeutic considerations of this rare disease along with a review of reported cases in the literature