Mycotic abdominal aortic aneurysm induced by immunotherapy with bacille Calmette-Guérin vaccine for malignancy.

Successful surgical treatment of a mycotic abdominal aortic aneurysm infected with Mycobacterium bovis is described. The infecting organism can be traced to an intraneoplastic injection of bacille Calmette-Guérin (BCG) vaccine into a cutaneous malignant melanoma nodule 14 months before aneurysm detection (17 months before operation). Treatment consisted of aneurysm excision, in situ prosthetic graft placement, and antituberculous medications. This patient represents the first reported case of BCG-induced mycotic aortic aneurysm.