Multiple Intracardiac Masses: Myxoma, Thrombus or Metastasis: A Case Report

Wei-Chieh Lee; Min-Ping Huang; Morgan Fu

Disclosures

J Med Case Reports. 2015;9(179) 

In This Article

Case Presentation

A 49-year-old Asian woman without systemic disease was admitted to our hospital with a 2-week history of progressive exertional dyspnea, orthopnea, bilateral lower limb edema and palpitation. Previously, she had been in good health except for mildly elevated blood pressure. A physical examination revealed a blood pressure of 195/138mmHg and a rapid pulse rate of 163 beats/minute. Jugular venous distention to 18 cm was noted, a chest examination revealed bilateral lower lung crackles, and a cardiac examination showed an irregularly rapid beat without an audible murmur. No palpable mass was detected in her neck, axillary or inguinal areas. Her lower limbs showed grade II edema. An electrocardiogram showed atrial flutter. Chest radiography showed a lower left lung patch and bilateral lung infiltration (Fig. 1). A hemogram showed leukocytosis and a high D-dimer (14.14mg/L). Biochemistry test results revealed renal insufficiency (creatinine 3.11mg/dL) and high serum lactic dehydrogenase (LDH) (1367U/L) and uric acid (20.9mg/dL) levels. Mildly elevated troponin-I (0.067ng/mL), creatine kinase-MB (CK-MB) (11.9ng/mL and B-natriuretic peptide (BNP) (704pg/mL) were also present. Transthoracic echocardiography (TTE) showed one fixed round hyperechoic mass with central necrosis over the left ventricular apex, one oscillating hyperechoic nodule over the anterior mitral annulus and one irregular and heterogeneous mass bulging out from the lateral wall of the right atrium (RA) (Figs. 2 and 3; Additional file 1: Video S1 http://www.jmedicalcasereports.com/content/9/1/179/additional).

Figure 1.

Lower left lung patch (white arrow) and bilateral lung infiltration

Figure 2.

On transthoracic echocardiogram, one irregular and heterogeneous mass (5.6cm2) over the lateral wall of the right atrium (RA) (white arrow)

Figure 3.

One fixed round hyperechoic mass with central necrosis over the left ventricular apex (upper black arrow), and one oscillating hyperechoic nodule over the anterior mitral annulus (lower black arrow). LV: left ventricle

Multiple intracardiac masses were noted, and malignancy was suspected. Elevated tumor markers were noted, and her cancer antigen 125 (CA-125) level was 298.10U/mL, cancer antigen 199 (CA-199) was 52.00U/mL and cancer antigen 153 (CA-153) was 33.80U/mL. Cardiac magnetic resonance imaging (MRI) was arranged for differential diagnosis of multiple intracardiac masses. The image showed one 6.0 × 2.3cm lobulated mass bulging out from the lateral wall of the RA along with another two small nodules in the left ventricular apex and anterior aspect of the mitral valve. The one RA mass and two LV masses did not invade into the cardiac walls. All masses were near isointense on T1-weighted image (T1WI) and hyperintense on T2-weighted image (T2WI). We favored a multiple myxoma diagnosis (Fig. 4).

Figure 4.

On cardiac magnetic resonance imaging (MRI) as cardiac-gated, cine gradient-echo "bright blood" magnetic resonance images, one 6.0 × 2.3cm lobulated mass bulging out from the lateral wall of the right atrium (RA) (a, b, c; black arrows) and another small nodule in the left ventricular apex (d; black arrow). LV: left ventricle

On enhanced chest computed tomography (CT), a consolidated patch with central necrosis over the lower left lung and enlarged left anterior mediastinal and right paratracheal lymph nodes were also noted (Fig. 5). However, no definite lung nodule or mass or pulmonary embolism was detected on her chest CT scan. Despite these findings and the high tumor marker, we could not differentiate between diagnoses of multiple myxomas or multiple metastatic lung tumors.

Figure 5.

On enhanced chest computed tomography (CT), a consolidated patch with central necrosis over the lower left lung (white arrow)

Heparinization was administered and her sinus rhythm spontaneously returned 2 days after medical treatment for heart failure and atrial flutter. Fortunately, her renal function improved and her serum LDH and uric acid levels returned to normal a few days later. We arranged a lung biopsy and echo-guided cardiac biopsies for an advanced etiologic survey. However, repeat cardiac biopsies and lung biopsies can only detect necrotic tissues or blood clots. Therefore, an open-heart biopsy and tumor excision were performed 3 weeks later and showed an RA lateral wall tumor with clots over its surfaces. The tumor extended to the RA auricle at the junction among the superior vena cava (SVC), RA and inferior vena cava (IVC). RA mass pathology with a 10 times view showed myxoma (5.1 × 3.1 × 1.5cm 3) in which the left side was composed of muscle cells and the right side contained bland-looking, oval-shaped stellate tumor cells on a fibromyxoid background (Fig. 6). Interestingly, no mass was found in the LV, and the thrombus disappeared after heparinization.

Figure 6.

Ten times view showed that the left side was composed of muscle cells and the right side showed bland-looking oval-shaped stellate tumor cells on a fibromyxoid background (black arrows)

The final diagnosis was RA myxoma and LV thrombi that resolved after heparinization. At a follow-up 1 year after surgery, our patient had returned to her daily activities, and all laboratory data, including tumor markers, had returned to normal ranges. Subsequent TTE showed adequate LV performance, and there were no further atrial flutter episodes. The consolidated patch over the lower left lung, which we favored as an arrhythmia- or myxoma-related emboli-induced lung patch, also resolved 1 month later. We suspected that initially elevated tumor markers and high uric acid and high LDH levels were related to necrotic tumor-derived tissue, decompensated heart failure with pleural effusion and renal insufficiency.

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