Pulmonary granulomas in a patient on MER therapy

A patient with metastatic melanoma developed symmetric miliary infiltrates of the lungs while receiving injections of MER into tumor containing lymph nodes of the groin. Open lung biopsy identified the pulmonary lesions as caseating epithelioid granulomas. After cessation of MER therapy, the pulmonary lesions regressed spontaneously. The possible etiology of this so-far-unreported complication of MER therapy was briefly discussed.