Postmortem diagnosis of fulminant infectious mononucleosis

Fulminant infectious mononucleosis (FIM) is a rare but life-threatening complication of Epstein-Barr virus infection that usually affects immunodeficient individuals. It is a hyperinflammatory syndrome caused due to release of massive amount of various cytokines, leading to hemophagocytic lymphohistiocytosis on histopathology, and a plethora of clinical manifestations due to simultaneous involvement of multiple organs of the body. The case of a young male who presented with fever and dyspnea and died within 12 h of presentation to the hospital was taken for autopsy. The postmortem evidence of hemophagocytic lymphohistiocytosis in the spleen, bone marrow, lymph nodes, liver, and lungs and the presence of large, basophilic intranuclear inclusions that stained latent membrane protein-1 positive on immunohistochemistry led to the diagnosis of FIM.