Clinical History
Patient 1: 31 year old female patient with tuberous sclerosis (TS).
Patient 2 (complementary case) : 32 year old male patient with TS.
Imaging Findings
Patient 1: Non-enhanced trans-axial chest CT images viewed with soft tissue window at the level of the heart shows a subtle intramyocardial fat focus in the free wall of the left ventricle (arrow).
Patient 2 (complementary case): IV-contrast-enhanced trans-axial chest CT image viewed with soft tissue window at the level of the heart shows a subtle intramyocardial fat focus in the interventricular septum near the left ventricular apex (arrow).
Discussion
Although tuberous sclerosis (TS) patients are famous for developing cardiac rhabdomyomas among other multisystemic hamartomatous lesions, this kind of cardiac abnormality is typically seen in the paediatric age group. The reason cardiac rhabdomyomas are not encountered in adult TS patients is because they appear and regress early in life.
A more common cardiac TS finding in adults is the presence of intramyocardial fat foci, which can be seen in more than half the patients. It is believed that such a lesion is part of the overall hamartomatous nature of the disease. The recent radiology literature highlights this finding and suggests adding it to the overall diagnostic TS criteria.
Intramyocardial fat foci in TS patients are described as well defined, non-invasive and non-enhancing. In contrast to post-infarction myocardial fatty metaplasia, intramyocardial fat foci of TS are seen in younger patients and do not confirm to known myocardial vascular territories.
It is important to note that intramyocardial fat foci of TS can be easily missed, since they can be subtle in some cases. In addition, the non-gated nature of regular chest CT examinations might obscure their presence. Thus, such lesions should be actively perused on CT chest studies when performed on known TS patients.
Differential Diagnosis List
Intramyocardial Fat Foci in Tuberous Sclerosis Patients
Final Diagnosis
Intramyocardial Fat Foci in Tuberous Sclerosis Patients
