Bilateral pulmonary nodules and intravascular pulmonary histiocytosis: A rare presentation of hemophagocytic lymphohistiocytosis secondary to Epstein-Barr Virus infection

A 61-year-old male presented with worsening dyspnoea and constitutional symptoms for few weeks followed by bloody diarrhoea and loss and fever. Physical exam revealed tachycardia, respiratory distress, and splenomegaly without lymphadenopathy. Work up showed pancytopenia, hypofibrinogenemia, acute kidney injury requiring haemodialysis, high ferritin level, positive IgG and IgM for EBV and positive soluble CD25. Chest CT scan showed bilateral pulmonary nodules. Lung biopsy showed intravascular pulmonary histiocytosis while bone marrow biopsy was negative for hemophagocytes. A diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made based on fulfilling the diagnostic criteria and systemic steroids were initiated, which improved the patient's condition gradually with resolution of dyspnoea, AKI and pancytopenia. Repeat chest CT scan showed resolution of bilateral pulmonary nodules. The patient was transferred to a tertiary centre to receive HLH-specific therapy. We present a rare presentation of HLH with steroid-responsive bilateral pulmonary nodules and a rare histopathologic finding of pulmonary intravascular histiocytosis, which has never been described in HLH or the lung tree.