Pacemaker pocket histoplasmosis - A rarest of rare CIED infection.

Cardiac Implantable Electronic Device infections continue to pose a pivotal threat to the successful management of various cardiac electrical disturbances. We present a case of a 79-year-old male who had undergone a dual-chamber pacemaker implantation 10 years ago. Patient presented with a history of fluctuant swelling over the pacemaker pocket, which has been slowly increasing in size over the past 1 year. There were no other signs of infection. Patient was approaching the pacemaker generator replacement indication. The patient underwent complete enucleation of the pacemaker pocket and replacement of the pacemaker generator. On histopathological examination of the specimen, Histoplasma spores were seen within macrophages of the specimen, confirming the diagnosis of histoplasmosis. The patient was further treated with antifungal therapy.