Case Presentation: A 20-year-old female presented to the emergency department with weakness and fatigue. She reported new onset midsternal chest pain that began approximately twelve hours prior to admission. She had noticed episodes of palpitations and tachycardia over the course of the past two months for which she was prescribed metoprolol tartrate, with no relief. She noted low-grade fever and malaise over the preceding five days, but had no other complaints

On admission, electrocardiogram was significant for sinus tachycardia without ST segment changes, labs were notable for an elevated troponin I of 0.112 ng/ml (normal: 0.000-0.032 ng/ml) and CT angiography significant for a small pericardial effusion and no pulmonary embolus. Transthoracic echocardiography (TTE) was normal with preserved LV function and no structural abnormalities. In light of a normal TTE and elevated troponin a cardiac MRI was ordered which revealed two large masses in the right atrium attached to the interatrial septum as well as a small circumferential pericardial effusion. CT abdomen was significant for three infiltrative non-obstructing retroperitoneal and small bowel masses as well as peritoneal carcinomatosis, CT guided biopsy was significant for Burkitt’s Lymphoma. She was treated with hyper-CVAD R (Cyclophosphamide, Vinicristine, Doxorubicin, Dexamethasone, Rituximab). Following treatment, repeat cardiac MRI showed resolution of the right atrial mass

Discussion: Cardiac masses are extremely rare and often times difficult to diagnose. They can be differentiated into primary and secondary tumors, with secondary masses being more common. 10-12% of patients diagnosed with any form of cancer have cardiac metastasis, with metastatic lymphoma being the most common. Primary cardiac tumors are extremely rare with a prevalence of 0.001-0.03% in autopsy series. TTE is the initial diagnostic test to evaluate for functional and structural cardiac abnormalities. Cardiac MRI is more sensitive in identifying structural abnormalities and is often ordered when TTE is inconclusive. As in the case presented, cardiac MRI was more sensitive in detecting structural abnormalities than TTE.

Conclusions: The clinical presentation of an intracardiac mass is variable and can include tachycardia, shortness of breath and palpitations. In young patients with unexplained persistent tachycardia it is important to determine the source of the tachycardia as it can be the initial presentation of a primary or metastatic malignancy.