Clinical Problem Solving: Signals from the Septum

Abstract Granulomatous inflammation involving the heart and intrathoracic or abdominopelvic lymph nodes presents a substantial diagnostic challenge; the differential spans infectious, inflammatory, and malignant conditions. Clinical features are often nonspecific, imaging patterns may overlap, and tissue samples can show mixed or evolving histologic findings. Cardiac involvement further complicates the picture, as both infectious and noninfectious granulomatous diseases can affect conduction pathways and structural integrity, sometimes with subtle or atypical presentations. We present a case of a middle-aged man with chronic constitutional symptoms, progressive conduction system disease, and fluorodeoxyglucose (FDG)-avid lymphadenopathy, whose evaluation required careful integration of clinical history, advanced imaging, and tissue diagnosis to arrive at the underlying cause.