Abstract 1122: A 32-Year-Old Woman with Progressive Shortness of Breath and Fatigue
A previously healthy 32-year-old woman presented with one month of fatigue, exertional dyspnea, and pleuritic chest pain. Examination was notable for hypotension with a pulsus paradoxus of 16 mmHg, elevated jugular venous pressure, decreased breath sounds and distant heart sounds. Chest radiography disclosed moderate cardiomegaly, electrocardiography demonstrated sinus tachycardia with low QRS voltage, and a chest CT was notable for a moderate pericardial effusion. A transthoracic echo demonstrated a large pericardial effusion with echocardiographic signs of tamponade. A pericardiocentesis removed two liters of sanguinous fluid which yielded negative cultures and cytology. Within one day the patient began to have recurrent symptoms, and a repeat echo demonstrated reaccumulation of fluid. Surgical drainage was performed with placement of a pericardial window. Initially the patient improved clinically. However, within one week, she developed recurrent dyspnea and chest pain with reaccumulation of fluid noted on echo. Given the patient’s recurrent effusions of unclear etiology and non-response to drainage, a cardiac magnetic resonance (CMR) was chosen as the next diagnostic test in order to directly image both the pericardium and mediastinum and to provide tissue characterization of the pericardial fluid. The patient’s CMR revealed a large, intrapericardial mass overlying the right atrium and ventricle with extension into the mediastinum. On delayed enhancement images, tissue characterization of the mass showed both vascularity consistent with a neoplasm and avascular tissue characteristics consistent with thrombus. Surgical exploration and subsequent pathologic examination confirmed these findings and the diagnosis of monophasic synovial sarcoma was made. This rare sarcoma is typically found in the soft tissue of the extremities with only eleven reported cases in the literature involving the pericardium. This case illustrates the importance of the history and bedside assessment in formulating a differential diagnosis. Ultimately, clinical considerations helped to guide a rational imaging approach that established the diagnosis based on tissue characteristics rather than anatomic appearance of a challenging pericardial mass.