Abstract
INTRODUCTION
Epipericardial fat necrosis (EFN) is an uncommon self-limiting benign condition that curses with chest pain. The first case was reported in 1957 and since than only few cases were reported. Recently, new imaging modalities have increased its diagnosis.
CASE REPORT
An otherwise healthy 42 years-old man presented with severe left-sided pleuritic chest pain, non-radiating, with 4 days duration, mildly relieved by an analgesic. No other symptoms nor history of infection. Physical examination, chest x-ray (CXR), ECG, routine laboratory testing, d-dimer and troponin measurements were unrevealing. Chest CT with contrast showed an increased density of anterior pericardial fat with nodular appearance consistent with EFN. The transthoracic echocardiogram was normal. For better characterization, a cardiac MRI was performed, and confirmed a small nodular lesion (10x17mm) with regular contours, externally to the pericardium, in relation to the apex of the right ventricle and the anterior thoracic wall (hypersignal on T1 and T2, loss of signal in fat saturation sequences, no contrast capture during the first pass nor late enhancement). The mass was delimited from the remaining pericardiac fat by a regular halo. Combined antiinflamatory therapy was started with favourable evolution. Cardiac surgery concluded that there was no need to perform a biopsy of the lesion unless there was recurrence of the symptoms. At 3 and 6-month follow-up, chest pain had resolved (no recurrence) - CT was performed for comparison and still showed a slight densification of the anterior mediastinum’s fat.
DISCUSSION
EFN is an often-overlooked etiology of chest pain in patients with a negative cardiopulmonary workup. The aetiology of EFN is still unknown but appears to be similar to other analogous conditions such as epiploic appendagitis and fat necrosis in the omentum or breast. It’s not expectable that patients with EFN have a higher risk of coronary heart disease. Onset is usually acute but can persist up to a year. Increased heart rate and diaphoresis may be found. ECG and lab tests are usually normal. CXR often shows a paracardiac opacity, occasionally with an associated pleural effusion. CT typically shows a fatty lesion anterior to the pericardium, in the epipericardial fat, with stranding of surrounding soft tissue. In most cases the adjacent pericardium is also thickened. CT enables prompt diagnosis in most cases, preventing further invasive procedures. No evidence-based treatment guidelines are available due to the rarity and benign behaviour of the disease. Treatment is usually conservative with analgesics and non-steroidal anti-inflammatory drugs. Follow-up imaging is recommended to confirm resolution and exclude neoplastic diseases such as liposarcoma. It is important to be familiar with its features since the clinical and radiologic characteristics suggest a presumptive diagnosis, thereby avoiding more aggressive techniques.
Abstract P1346 Figure. MRI - small nodular lesion
Imaging Manifestations of Mediastinal Fat Necrosis