A 50-year-old woman presented for evaluation of an enlarging right cardiophrenic angle mass. Two years prior she complained of intermittent nausea, diarrhea, and flushing. Initial chest radiography and computed tomography (CT) suggested a pericardial cyst. Due to the onset of increasing dyspnea on exertion, lower extremity edema, and weight gain repeat CT was performed revealing a solid tumor. An Indium-111 octreotide scan showed somatostatin activity limited to the pericardiac mass. Histology after resection confirmed the diagnosis of peripheral bronchial carcinoid. The traditional differential diagnosis for a right cardiophrenic angle mass was misleading in this patient.