A 12-year-old girl undergoes bone marrow transplant as pa of therapy for ALL. She subsequently presents with pulmonary complaints and neurologic findings. Lung biopsy reveals a granulomatous vasculitis with associated atypical lymphocytes. Clonality studies reveal a monoclonal B cell population with associated polyclonal T cells. What infectious agent is related to this diagnosis?
High-Yield Explanation
The clinical and histologic findings are consistent with lymphomatoid granulomatosis, an EBV associated B cell neoplasm which is most commonly seen in pulmonary and CNS vessels in the setting of immunosuppression. Abundant reactive T cells are also seen, which led to early confusion about whether this entity primarily represented a B cell or T cell process.