A Slow Burning Diagnosis: A Case Report of Hemophagocytic Lymphohistiocytosis Preceding the Diagnosis of Subcutaneous Panniculitis-Like T-Cell Lymphoma

HLH is a severe inflammatory syndrome characterized by primary or secondary immune dysregulation causing excess activation of macrophages and cytotoxic lymphocytes, leading to multi-system dysfunction. Diagnosing and managing HLH can be challenging for clinicians, with HLH-2004 criteria for diagnosis requiring a molecular diagnosis or the presence of at least five of the following: fever, splenomegaly, cytopenia involving two or more cell lineages, hypertriglyceridemia and/or hypofibrinogenemia, hemophagocytosis in the bone marrow, spleen or lymph nodes with no evidence of malignancy, low or no NK cell activity, elevated ferritin, or elevated soluble IL-2 receptor. These criteria have been utilized to develop the HScore, a tool used to assist in determining the probability of HLH based on the aforementioned abnormalities. After diagnosis, treatment typically includes chemotherapy and immunosuppression, followed by allogeneic bone marrow transplant.