nonencapsulated adipose tissue forming a lipomalike mass, usually in the cardiac interatrial septum where it may cause arrhythmia and sudden death. Synonym(s): lipomatous hypertrophy
li·po·ma·tous in·fil·tra·tion
(li-pō'mă-tŭs in'fil-trā'shŭn) Nonencapsulated adipose tissue forming a lipomalike mass, usually in the cardiac interatrial septum where it may cause arrhythmia and sudden death.