Natural Killer/T-Cell Lymphoma-Associated Hemophagocytic lymphohistiocytosis—a Rare and Dangerous Disease

Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome characterised by the reactive activation of cytotoxic T-lymphocytes and macrophages along with a substantial amount of cytokine secretion caused by various inductions. Natural killer/T-cell lymphoma (NKTL)-associated HLH (NK/T-LAHLH) is rare in clinical practice with an incidence rate of 7.1-11.9% in NKTL patients. Currently, there is no standard first-line treatment with good efficacy for NK/T-LAHLH. The treatment of NK/T-LAHLH is still mainly based on chemotherapy regimens containing etoposide and dexamethasone. Recently, many new therapeutic drugs and schemes have been trialled for the treatment of NK/T-LAHLH, such as ruxolitinib, immune checkpoint inhibitors, pegaspargase, and the DEP regimen. However, NK/T-LAHLH is associated with overall poor prognosis. Improving overall understanding of NK/T-LAHLH is of great significance to ameliorating patient prognosis. This review systematically discussed the epidemiology, pathogenesis, clinical features, current treatment regimens, and prognosis of NK/T-LAHLH to comprehensively elucidate this disease.