1339485 - Radiologic evaluation of a left ventricular mesenchymal hamartoma

A 44-year-old female with no significant cardiac or family history presented to a community hospital with multiple syncopal episodes over 3 weeks. On arrival, echocardiogram showed a large mass within the left ventricular wall. Follow-up imaging was confirmatory. Telemetry monitoring suggested narrow complex supraventricular tachycardia with runs of ventricular tachycardia attributed to the mass. Patient was started on BB therapy and fitted for a Life Vest, with recommendations for resection. The patient was referred to a tertiary care center for surgical treatment and mass removal was performed without complications. Pathology interpretation showed mesenchymal cardiac hamartoma.

Diagnostic Techniques and Their Most Important Findings:

Cardiac MRI confirmed ultrasound findings of an approximately 5 cm x 5 cm mass. It was T2 hyperintense, T1 isointense, demonstrated robust heterogeneous first pass perfusion enhancement, and showed intense homogenous delayed gadolinium enhancement. This favored a fibroma but with the early heterogenous first pass perfusion enhancement the possibility of a hemangioma could not be excluded. LVEF was 50% and there was local mass effect. CT Chest/A/P showed the enhancing mass with no additional foci concerning for metastasis. A coronary angiography was performed and depicted a vascular LV mass perfused by a branch of the LAD diagonal over the anterolateral wall.

Learning Points from this Case:

Primary cardiac tumors are rare and usually benign. However, they can cause non-specific symptoms including syncope, arrythmia, and chest pain with potentially lethal consequences. Imaging plays a critical role in detection, diagnosis, and operative planning. A cardiac hamartoma is a benign overgrowth of mature cardiac myocytes in a disorganized fashion. There can also be a mix of vascular, fibrous, and fatty tissue with the LV free wall being the most common location. Echocardiography is generally used initially for localization. MRI is the modality of choice as it allows for hemodynamic evaluation and tissue characterization to help with diagnosis. CT is best suited for demonstration of fat and calcifications. Coronary angiography can help define the vascular supply and assist with surgical technique. Ultimately, imaging can help narrow down the differential, but final diagnosis must be made by histologic examination.