Summary

Lymphomatoid granulomatosis (LG) is a rare Epstein-Barr virus-driven lymphoproliferative disorder that generally arises in immunosuppressed patients and which can be life-threatening. Here we describe the development of pulmonary LG in a patient on long-term azathioprine for immune-mediated neuropathy. Although azathioprine carries a boxed warning for malignancy, its association specifically with LG, an otherwise rare entity, is poorly recognised. Early recognition of drug-induced LG is critical, since discontinuation of the offending agent, and implementation of effective therapy can provide rapid clinical benefit in some patients. In this case, rituximab was used as an effective treatment for LG, which also provided an additional benefit of controlling the patient's underlying neuropathy. Further research is needed to identify vulnerable patients who are at high risk of developing drug-induced LG.