Abstract

Hemophagocytic Lymphohistiocytosis - Case History and Review of Literature

Sasidharan PK and Priyadarshini B

Hemophagocytic lymphohistiocytosis or HLH is a very rare underdiagnosed potentially fatal entity which frequently leads to multiorgan failure and death due to immune dysregulation. It can be either primary which is supposed to be an inherited disorder seen in infancy and childhood or secondary to infections, connective tissue disorders or malignancies which is seen in all ages. The disease manifestation is due to massive release of inflammatory cytokines (cytokine storm) into the circulation which is out of control of the immune system. The cytokines activate the macrophages which lead to phagocytosis of the hemopoietic cells including precursors leading to cytopenias. Clinically it is mistaken for bone marrow infiltrating diseases like leukemia, lymphoma, and several other entities. It is important to have a high index of suspicion for diagnosis since an early diagnosis is crucial to decrease the significant mortality associated the disease. The definitive diagnosis still remains a challenge due to the varied clinical presentations with which this disease can present. This article gives two case histories and reviews the varied clinical presentations, pathophysiology, prognosis and treatment of the entity.