An intrapericardial mass with features of teratoma as a rare cause of acute coronary syndrome: a case report and 4-year follow-up

ABSTRACT. The present clinical case demonstrates a rare variant of acute coronary syndrome, in which the most likely mechanism of myocardial ischemia was extrinsic compression of a coronary artery by an intrapericardial mass with magnetic resonance imaging features of a teratodermoid tumor. A 47-year-old woman was admitted with clinical signs of acute coronary syndrome with ST-segment elevation. Echocardiography revealed regional left ventricular wall motion abnormalities and a mass in the pericardial cavity adjacent to the anterior and anterolateral walls of the left ventricle. Contrast-enhanced cardiac magnetic resonance imaging showed a well-defined heterogeneous mass measuring 33 × 43 × 41 mm with features consistent with a teratodermoid lesion. The differential diagnosis included cardiac and pericardial tumors, metastatic disease, and visceral syphilis. The patient refused biopsy for morphological verification of the mass, as well as surgical treatment. During four years of follow-up, clinical deterioration associated with progression of chronic heart failure was observed. Thus, this case demonstrates a rare “non-classical” cause of the clinical presentation of “classical” acute coronary syndrome and is intended to broaden physicians’ understanding of the etiology of myocardial ischemia.

For citation: Gasanov MZ, Sokolovskaya AV, Gasanova AV, Kolomatskaya OE, Chulkov VS, Veber VR. An intrapericardial mass with features of teratoma as a rare cause of acute coronary syndrome: A case report and 4-year follow-up. Therapy (Moscow). 2026;12(5S):132–137.
https://doi.org/10.18565/therapy.2026.5-s5.132-137

INTRODUCTION

Cardiovascular diseases remain the leading cause of death in Russia and worldwide [1]. Coronary artery disease accounts for the largest proportion of cardiovascular deaths, with acute myocardial infarction and its complications contributing substantially to this burden [1, 2]. Acute coronary syndrome (ACS) is a major cardiovascular emergency that requires prompt diagnosis, early risk stratification, and timely selection of reperfusion and antithrombotic therapy [3, 4]. In most cases, acute coronary syndrome develops as a result of atherothrombotic coronary artery disease. In some patients, however, myocardial ischemia occurs in the absence of typical stenotic atherosclerotic coronary lesions, requiring a broader diagnostic work-up and consideration of non-atherosclerotic mechanisms of ischemia [5].

Non-atherosclerotic causes of ACS include spontaneous coronary artery dissection, coronary vasospasm, embolism, microvascular dysfunction, congenital coronary artery anomalies, inflammatory involvement of the vascular wall, and extrinsic compression of a coro­nary artery by tumors or other cardiac, pericardial, and mediastinal masses [5, 6]. The latter mechanism is extremely rare but is clinically important, since standard antianginal, antithrombotic, and lipid-lowering therapy does not eliminate the mechanical cause of impaired coronary blood flow.

Tumors, particularly those located in the mediastinum, may be considered rare causes of ACS because, as they increase in size, they can compress adjacent tissues, including the heart and coronary arteries [7]. Intrapericardial teratomas are rare tumors of embryonic origin and are much more commonly detected prenatally [8], in newborns, and in early childhood [9, 10]. In adult patients, such lesions have been reported only in isolated cases; they may remain asymptomatic for a long time [11, 12] or manifest as a result of compression of the cardiac chambers, great vessels, or coronary arteries [13, 14]. Echocardiography, coronary angiography, computed tomography, and contrast-enhanced cardiac magnetic resonance imaging (MRI) play an impor­tant role in the diagnosis of cardiac, pericardial, and mediastinal masses, allowing assessment of the lesion’s location, size, and structure, as well as its relationship with surrounding anatomical structures [15]. In symptomatic cardiac and pericardial masses, especially those accompanied by compression of the heart and vessels, early radical surgical removal is generally considered the preferred strategy, as it can eliminate mechanical effects on adjacent tissues and provide definitive morphological verification of the diagnosis [16, 17].

This report describes a rare case of ACS in a woman, presumably caused by extrinsic compression of a coronary artery by an intrapericardial mass with MRI features of a teratodermoid tumor. Our group previously presented the case in conference proceedings in 2018, during the patient’s initial examination and diagnostic evaluation [18]. We now report the findings from 4 years of follow-up after the patient declined surgical treatment.

CASE REPORT

Patient K., a 47-year-old woman, presented with a two-week history of progressively worsening retrosternal and left subscapular burning pain. The pain occurred with minimal physical exertion and was not relieved by nitroglycerin. She also reported exertional dyspnea during ordinary activities, palpitations, and episodic blood pressure elevations to 150/90 mm Hg. She did not seek medical care during this period.

On the night of admission, she experienced severe interscapular pain lasting approximately 30 to 40 min, radiating to both arms, and accompanied by numbness. She also had palpitations, severe dyspnea, and a sense of impending doom and sat leaning forward to breathe more comfortably. She was admitted to her local district hospital for suspected ACS. Electrocardiography (ECG) showed ST-segment elevation and ischemic changes in the anteroseptal region. Echocardiography demonstrated moderately reduced global left ventricular systolic function and hypokinesia of the anterior and anteroseptal walls. Left ventricular hypertrophy and thickening of the aortic and mitral valve leaflets were also noted.

The patient received treatment with acetylsalicylic acid, a beta-blocker, an angiotensin-converting enzyme inhibitor, and a statin. Despite treatment, chest pain, anteroseptal ECG abnormalities, and frequent premature ventricular complexes persisted. She was therefore referred to the Regional Clinical Hospital for cardiology consultation.

At the regional hospital, the patient was hemodynamically stable but moderately ill. Physical examination showed a prominent apical impulse, leftward displacement of the left cardiac border on percussion, an accentuated aortic component and splitting of the second heart sound. Blood pressure was 165/100 mm Hg, and heart rate was 84 beats/min.

Because symptoms and the previously documen...

M.Z. Gasanov, A.V. Sokolovskaya, A.V. Gasanova, O.E. Kolomatskaya, V.S. Chulkov, V.R. Veber