Hemophagocytic Lymphohystiocytosis in a Patient With Suspected Acute Myeloid Leukemia and Recent Viral Illness Compatible With Dengue: A Case Report and Literature Review

BACKGROUND: Hemophagocytic lymphohistiocytosis, or HLH, is a very rare and aggressive disorder of the immune system, for which the trigger may be an infection, malignancy, or autoimmune disease. It has predominantly been described as triggered by T/NK lymphomas, but acute myeloid leukemia-induced HLH is a very rare occurrence. Viral infections like dengue fever may act as potential triggering factors. CASE PRESENTATION: A 24-year-old male developed persistent high fever, weakness, and pancytopenia a few days after recovery following a recent febrile illness clinically compatible with dengue infection in a dengue-endemic setting, supported by IgG seropositivity (IgM negative). He was found to be reactive for hyperferritinemia, coagulopathy, and hepatopathy. Bone marrow biopsies revealed blasts of 78%, which were suggestive of AML and myelomonocytic differentiation but also reflected abnormalities in the chromosomes t(1;9)(q42;q22), add(11)(q23). DISCUSSION: This is an instance of an extremely rare and critical manifestation of HLH, coinciding with suggestive AML, seemingly triggered by an acute dengue illness. In our literature search, there were a few instances of AML and HLH, either preceding AML, concurrent, or post-AML, mainly in younger individuals with high-risk cytogenetics and an aggressive disease course. Generally, the prognosis in these instances turned out to be poor, mainly for those who experienced a delay in diagnosis and management or those complicated with infections and chemotherapy. In the given scenario, the patient suffered from severe complications in the initial stage, including disseminated intravascular coagulation, but responded to supportive care, and his clinical condition was stabilized. Later, the patient was shifted to a referral institute for management, and further prognosis information was not obtained. CONCLUSION: This particular case illustrates the importance of considering the possibility of HLH in the setting of unexplained systemic inflammation with the presence of an identified hematologic malignancy and preceding infection by a virus. However, the prognosis for patients with concomitant diagnoses of both HLH and AML is not encouraging.