Cardiac Inflammatory Myofibroblastic Tumor: A “Benign” Neoplasm That May Result in Syncope, Myocardial Infarction, and Sudden Death

Abstract

Cardiac tumors other than myxomas are rare. We report a series of 10 intracavitary polypoid myofibroblastic proliferations in children and young adults emphasizing gross, histologic, and clinical features. There were 6 females and 4 males, with a mean age of 10 years (range 5 wk to 21 y). All lesions were endocardial-based, located in the right atrium (1), right ventricular inflow/tricuspid valve (1), right ventricular outflow (3), mitral valve (3), aortic valve/left coronary sinus (1), and left ventricular free wall (1). Symptoms included shortness of breath or dyspnea (3), syncope (2), chest pain (1), transient ischemic attacks (1), and fever with myalgias (1). All tumors were surgical resections, except 1 tumor that resulted in sudden coronary death and that was diagnosed at autopsy, and 1 tumor that embolized into the coronary artery and was treated by cardiac transplant. Two tumors, present in the aortic and mitral valves, respectively, caused cardiac ischemia. The tumors were polypoid or filiform and histologically resembled inflammatory myofibroblastic tumors of extracardiac sites, with loose spindle cell growth with sparse inflammation. Although there were frequent collagen bundles interspersed among the tumor cells, there were no large areas of dense fibrosis. Surface fibrin was present on the polypoid projections in 7 cases. Symptoms resulted from prolapse into coronary ostia or embolization, but no patient developed metastasis. Long-term follow-up in 2 patients demonstrated no evidence of disease or recurrence. Although metastatic potential was not identified, these tumors may result in serious symptoms, including myocardial infarct, syncope, and sudden death. These cardiac myofibroblastic tumors are readily distinguished from other endocardial-based cardiac tumors, including papillary fibroelastoma and myxoma, which may present clinically in the same manner.

Febrile Illness in an Infant With an Intracardiac Inflammatory Myofibroblastic Tumor

“…ALK-1 is positive in 35% of IMTs, 11 although a negative result does not rule out the diagnosis because several intracardiac IMTs have previously stained negative. 2,8,12,13 IMTs are described as benign reactive lesions; although the exact etiology of the tumor is unknown, several studies have associated IMTs with Epstein-Barr infection. 8,[11][12][13] Listeria monocytogenes has also been reported to cause IMTs as well.…”

“…15 Poor prognosis is associated with lesions involving the coronaries, cardiac valves, or ventricular outflow tracts. 2,5 Although serum laboratory investigations may offer some information, diagnostic imaging is the mainstay for diagnosis of cardiac tumors. An echocardiogram is the most useful modality to confirm diagnosis of an intracardiac mass.…”

“…Deaths due to the tumor are related to its location in the heart; lesions located near the coronary arteries, cardiac valves, and ventricular outflow tracts, in particular, are associated with fatality. 2,5 …”

“…1 Of these, 33 have been reported in the pediatric population, with approximately half of this group involving children <12 months of age. 2 Although IMTs are generally described as benign tumors, a small number demonstrate neoplastic properties, such as local recurrence after resection. 3,4 The clinical presentation of IMTs often includes fever, respiratory distress, anemia, weight loss, and elevated inflammatory markers.…”

Pericoronary Pseudotumor Caused by Helicobacter Cinaedi

“…In our case, because the coronary pseudotumor had decreased in size with appropriate antibiotic therapy and showed no 18 F-FDG uptake, we decided on meticulous followup for this patient. Because such lesions can be associated with morbidity and mortality by affecting coronary arteries, cardiac rhythm and valvular function, 11,14) if the lesion increases in size and symptoms such as fever and chest pain recur, we will reassess it and operate if necessary. …”