Hemophagocytic lymphohistiocytosis following enteric fever: A rare autopsy case report.

Hemophagocytic lymphohistiocytosis (HLH) is a severe and frequently underdiagnosed disorder of systemic immune dysregulation resulting in hypercytokinemia and histologically evident hemophagocytosis, We report a case of a 34-year-old man who presented with breathlessness, generalized weakness, and fever of unknown origin with pancytopenia. Clinically the patient was admitted for febrile illness, and treated symptomatically but his general condition worsened leading to death within 21 hours of admission. A complete autopsy was performed. The deceased had a significant past history of repeated episodes of fever, weight loss, and axillary lymphadenopathy over a period of 8 months with multiple hospital admissions. He was also diagnosed with enteric fever (Widal test and Typhi IgM positive) at the start of these episodes. Hemogram during this period revealed persistent pancytopenia. Serum ferritin, serum triglycerides, and liver function tests were consistently deranged. Investigations for the etiology of fever and blood cultures were negative while the bone marrow aspirate revealed a normocellular marrow. CT abdomen-pelvis showed mild hepatomegaly with enlarged retroperitoneal lymph nodes. Infective endocarditis, lymphoma, and bronchopneumonia were being considered the clinical diagnoses. The significant autopsy findings were hepatosplenomegaly with retroperitoneal lymphadenopathy and multiple gastric ulcers. On microscopy, the liver, spleen, bone marrow, and lymph nodes showed characteristic hemophagocytosis. Post-mortem histopathological examination clinched the diagnosis of HLH and fulfilled six out of eight diagnostic criteria of the HLH-2004 protocol. We discuss the clinical course and diagnosis of this unique case and strive to create awareness about secondary HLH induced by common diseases, such as enteric fever.