Advanced heart block as a manifestation of a paraneoplastic syndrome from malignant thymoma

Malignant thymoma is a rare tumor that is associated with paraneoplastic syndrome. Myocarditis as a paraneoplastic syndrome has been rarely described. Reported herein is a young male patient with malignant thymoma and myocarditis as part of a paraneoplastic syndrome. This resulted in high-degree heart block and an asystolic cardiac arrest despite placement of a permanent pacemaker.