Cardiac Masses - Cases

1355142 - Large Intramyocardial Fibroma Mimicking Hypertrophic Cardiomyopathy

Thursday, January 26, 2023

7:00 AM – 7:50 AM

Location: Pacific Jewel

Presenting Author(s)

MA

Mohamed Abdelmotleb, MD

Cardiothoracic Imaging Fellow
University of Washington, United States

Primary Author(s)

MA

Mohamed Abdelmotleb, MD

Cardiothoracic Imaging Fellow
University of Washington, United States

Co-Author(s)

Karen Ordovas, MD, MAS

Professor of Radiology, Cardiothoracic Imaging Section Chief, Associate Vice-Chair for Academic Affairs
University of Washington
Kirkland, Washington, United States
Matthew Cham, MD

Professor of Radiology, Director of Cardiac MRI
University of Washington
KENMORE, Washington, United States
KS

Kyle Spearman, MD

Clinical Assistant Professor of Radiology
University of Washington, United States
MJ

Maham Jehangir, MD

Assistant Professor of Cardiothoracic Imaging
Rush University, United States
HC

Hamid Chalian, MD

Associate Professor of Radiology
University of Washington, United States

Disclosure(s):

Matthew Cham, MD: No financial relationships to disclose

Description of Clinical Presentation: A 42-year-old female patient was at a soccer game with friends when she suddenly felt progressively dizzy and started vomiting minutes later. Medics arrived and found her to be in ventricular tachycardia with heart rates in the 200s. Systolic blood pressure was 60. Cardioversion was attempted three times without improvement. Procainamide was then administered and the heart rate was restored to normal sinus rhythm.

Diagnostic Techniques and Their Most Important Findings: The initial plain radiograph in the emergency department showed an irregular contour of the left cardiac border. Transthoracic echocardiography revealed a mildly reduced left ventricular ejection fraction of 44% and severe hypertrophy of the left ventricle's anterior septal wall, measuring up to 2.2 cm. The primary consideration was a variant of hypertrophic cardiomyopathy, however, the focality and severity of the pathology prompted a suggestion to undergo a cardiac MRI for further characterization.

Cardiac MRI was performed the next day and revealed a 7.2 x 3.5 cm sharply-demarcated intramural left ventricular mass within the basal to mid anterior and anteroseptal walls. The mass was T1-isointense and significantly T2-hypointense, and demonstrated marked enhancement on delayed late gadolinium images. These findings were most suggestive of a cardiac fibroma.

PET/CT was also performed and showed minimal avidity within the mass, another finding compatible with a fibroma, which was the primary consideration at this point.

Biopsy and histopathological evaluation confirmed the final diagnosis to be a large intramyocardial fibroma.

Learning Points from this Case: Several modalities are currently used to assess cardiac masses, including echocardiography and computed tomography, but this case clearly highlights the advantages of cardiac MRI, namely its superior temporal resolution and tissue characterization. These qualities set cardiac MRI as the modality of choice for assessment of cardiac masses, in addition to its high capability to differentiate between mimics of hypertrophic cardiomyopathy.

Cardiac fibromas are rare tumors, usually found in the pediatric population and are much rarer when it comes to adult patients. They are associated with dyspnea, arrhythmias, and sudden cardiac death. Surgical treatment is the definitive treatment for symptomatic cases, including cardiac transplant. A large fibroma can a mimic of hypertrophic cardiomyopathy, but utilizing cardiac MRI's tissue characterization properties can greatly aid differentiation, where fibromas appear as well-circumscribed, T1-isointense, T2-hypointense masses with no significant enhancement on post-gadolinium imaging, although they demonstrate intense enhancement on late gadolinium enhancement (LGE). Such information can greatly aid patient's management and alter the course of treatment.