Abstract 12813: Left Main Disease—Not as Straightforward as It Seems

Abstract

A 51 year-old female with a past medical history of hypertension presents with chest pain that began 12 hours earlier. EKG showed biphasic T waves in the anterior leads and ST depressions in the lateral leads with a dynamic trend in troponins. LHC showed severe LM stenosis extending into the proximal LAD and LCx. An IABP was placed due to persistent angina despite being on a nitroglycerin drip. Given the minimal involvement the other coronary arteries, a coronary CT angiogram was pursued to evaluate for other non-atherosclerotic etiologies. The CT showed a periaortic soft tissue mass that encased the left main and the right pulmonary artery. The differential for conditions causing compression of the coronaries includes aortic or pulmonary artery aneurysms, abscesses, thymoma, lymphoma, teratoma and bronchogenic cysts. A PET scan showed metabolic activity of a supraclavicular lymph node, the mediastinal mass and a pericardial effusion. Her lymph node biopsy and mediastinal mass biopsy were consistent with a thymic carcinoma. Although thymomas are the most common anterior mediastinal tumor in adults, thymic carcinoma are rarer, more aggressive and thus spread outside the thymus. For thymic carcinomas, the ideal treatment is complete surgical resection while non-surgical candidates should undergo chemotherapy and radiation. Due to the proximity of the carcinoma the aorta and pulmonary artery, our patient was deemed not a surgical candidate and underwent radiation. This unique case highlights that non-athlerosclerotic etiologies should be entertained in cases of isolated left main disease and the importance of utilizing multimodality imaging to identify such causes.