Hemophagocytic lymphohistiocytosis (HLH) is a poorly understood, rare, and often unrecognized disease. It predominantly affects children, in whom well-established therapeutic protocols exist for this entity, but is increasingly being recognized in the adult population, where there is a lack of scientific data to develop and unify treatment guidelines. This scarcity of data is even more pronounced when evaluating the epidemiology of tropical, developing countries and resource-limited areas. Literature suggests that the epidemiology and clinical presentation of HLH may be different in these regions. This study aims to compare the epidemiology of international literature with that of developing regions while contributing to the data collected from adult patients with HLH at the Hospital Geral Dr. César Cals, who were hospitalized from 2019 to 2021. A retrospective analysis of medical records of 6 institutionalized patients during this period was conducted, allowing for the development of descriptive statistics and comparison of these data with the rest of the literature. The data collected in this study suggest an epidemiological approximation with cases in the literature from developing countries and important details regarding the diagnosis and treatment of HLH in these regions that are not well-covered by international literature. It is certainly necessary for healthcare professionals to have a high index of suspicion for this pathology, especially in developing countries, and for these cases to be more reported to enable the expansion of knowledge of this still-mysterious disease.
