Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Myxoma, Left Atrium
- Radiologic Findings
- Chest radiograph shows mild cardiomegaly and left cardiophrenic angle blunting, suggesting pleural effusion. Contrast?enhanced CT scan shows polypoid hypodense mass in the left atrium. The mass is attached to the interatrial septum. Small amount of pleural and pericardial effusions are combined.
Photograph of the gross specimen shows lobular pedunculated mass with multiple leaf like projections. Photomicrograph (HE stain) demonstrates nest of myxoma cells, and myxoid matrix. Immunohistochemical stain shows expression of calretinin of myxoma cells. Calretinin is expressed in about 75 % of cardiac myxoma.
- Brief Review
- Primary tumors of the heart are rare. Secondary malignant cardiac tumors, often arising in the lung and the breast, are at least 20 to 40 times more common than primary neoplasm. The majority of primary tumors are histologically benign.
Cardiac myxoma is the most common primary cardiac neoplasm, and accounts for approximately one-half of all primary cardiac tumors. Myxoma typically manifests as a polypoid, intracavitary left atrial mass (75 %) that arises from the interatrial septum, but it may originate in any cardiac chamber. Although most cases occur sporadically, familial lesions and lesions associated with a clinical complex have also been reported (carney complex).
Most affected patients present with at least one feature of a classically described triad that includes cardiac obstructive symptoms, constitutional symptoms (fever, malaise, weight loss, anemia, and elevated sedimentation rate), and embolic events.
Presenting complaints relate to tumor location, which predicts obstructive sequelae and influences embolic sites (pulmonary or systemic). Cardiac arrhythmias, atrial fibrillation, and atrial flutter reportedly occur in approximately 20% of patients with cardiac myxoma.
The histologic features of cardiac myxomas are distinctive but heterogeneous. The tumor cells form rings, nests, and linear syncytia. The amount of myxomatous stroma is widely variable. Hemorrhage, thrombus, and hemosiderin are common and calcification is also common.
Radiographic manifestations of 86 cases of cardiac myxoma were reviewed by Mary et al. Most patients with cardiac myxomas have abnormal but usually nonspecific radiographic findings. Radiographs of 38 patients with left atrial myxoma showed evidence of mitral valve obstruction in 53%; radiographs of 16 patients with right atrial myxoma demonstrated calcification and cardiomegaly in 56% and 50%. Other nonspecific manifestations such as cardiomegaly and pleural effusion occurred in 37% and 15% cases. One-third of all patients in this series had normal chest radiographic findings. CT demonstrates intracavitary heterogeneous, hypoattenuated (81%) lobular masses. MR imaging shows heterogeneous enhancing lesions and usually allows visualization of the point of attachment (78%). The differential diagnosis of an intracavitary cardiac mass includes thrombus and other much less frequent cardiac neoplasms, including sarcomas and papillary fibroelastomas. Left atrial thrombi are much more common than myxomas. They usually arise from the posterior and lateral atrial walls and from the atrial appendage. Left ventricular thrombi occur in regions of ventricular dyskinesia or aneurysm, and myxomas very rarely occur in this location.
- References
- 1. Mary LG, Melissa LR, Curtis EG, Allen PB, and Jeffrey RG. From the Archives of the AFIP: Cardiac Myxoma: Imaging Features in 83 Patients. RadioGraphics 2002; 22: 673-689.
2. Michael JP, Samuel VL, G. Fraank OT. Primary Cardiac Tumor: Fourty Years’ Experience with 71 patients. Cancer 1997;79: 1809-1815.
- Keywords
- Vascular, heart, Benign tumor,