1346290 - Multiple Myocardial Fatty Deposits in Tuberous Sclerosis: 10-Year Follow Up and Prognosis

Description of Clinical Presentation: A 49-year-old female was diagnosed with tuberous sclerosis complex (TSC) at age 21, when she presented for evaluation of skin lesions. At age 33, she had a mass removed from the left kidney due to increase in size which was confirmed to be angiomyolipoma. In addition, she was found to have multiple tumors and calcifications in the brain, lymphangioleiomyomatosis (LAM) of the lungs, multiple renal masses, multiple sclerotic bone lesions as well as involvement of the eyes, and skin. She established cardiology care 10 years ago, was found to have a cardiac mass by echocardiography, and has remained clinically asymptomatic and echocardiographically stable from a cardiac standpoint during her 10-year follow up. Given the diagnosis of TSC, the cardiac mass was felt to be most clinically consistent with a rhabdomyoma.  Currently, she is under evaluation for lung transplant due to worsening extensive LAM with increasing oxygen requirements.

Diagnostic Techniques and Their Most Important Findings: A chest CT was obtained for evaluation of pulmonary involvement and demonstrated a low attenuation mass in the left ventricle (LV) thought most consistent with a fatty lesion vs potential thrombus (Figure 1). A cardiac magnetic resonance (CMR) without gadolinium (severe renal dysfunction) was performed for further definition of the cardiac mass. A steady-state free precision cine imaging demonstrated normal biventricular size and function as well as a 3x1.8 cm encapsulated LV mass attached to endocardium located in mid-to-apical anterior and anterolateral regions. There was a small 8x6 mm, encapsulated, mass in the right ventricle (RV) free wall as well as multiple tiny focal intramyocardial lesions throughout the LV and RV (Figure 2). Native T1 mapping revealed low T1 values (ms) of these masses. T-1 and T-2 weighted imaging demonstrated hyperintense signal of the large mass which lost signal on fat saturated sequence (Figure 3). These findings were most consistent with multiple fatty deposits in the myocardium along with a lipoma vs potentially angiomyolipoma.

Learning Points from this Case: This case demonstrates the role of CMR in distinguishing rhabdomyoma from lipoma and myocardial fatty foci (MFF). While myocardial fatty deposition can be seen in various diseases including healed myocardial infarction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, and muscular dystrophy, MFF has been shown to be highly specific for TSC. There is a positive correlation between MFF presence and TSC gene mutation as well as the degree of multiorgan involvement. While our patient has severe multiorgan disease including cranial, pulmonary and renal manifestations, the cardiac manifestations of TSC were shown to be stable over a 10-year period follow up without any cardiac symptoms. Patients who are first diagnosed with MFF by CMR should undergo careful evaluation for multisystem disease.