Stalactites in the Right Ventricle

Abstract

Heart metastatic tumors are more frequent than primary heart tumors. Cardiac metastasis is a rare phenomenon, occurring mainly by direct spread, especially from lung cancer. Cardiac metastases may be asymptomatic or cause arrhythmias, nonspecific electrocardiographic alterations, or mimic a myocardial infarction. In this case report, we illustrate a rare case of pulmonary adenocarcinoma, which through the bloodstream developed a stalactite-shaped metastasis within the right ventricle of conspicuous size (20 mm × 34 mm × 12 mm). In addition, the tumor compressed the right pulmonary trunk, causing pulmonary hypertension. It is essential to characterize metastasis with multimodality imaging. Such lesions within the right cavities can cause massive pulmonary embolism, as in our case, leading to the patient’s death, thrombolytic therapy not being effective.

INTRODUCTION

Heart metastatic tumors are more frequent than primary heart tumors and occur in 21% of all patients with metastatic cancer.[1] Carcinoma of any type accounts for 76% of cardiac metastases: lung cancer, breast cancer, esophageal carcinoma, stomach cancer, malignant melanoma, lymphoma, and leukemia.[2] Lung cancer is the most common metastatic cardiac tumor, while breast carcinoma has an important incidence in females, but the highest rate of metastases occurs with malignant melanoma.[3] Heart cancer can cause arrhythmias, nonspecific electrocardiographic alterations, or mimic a myocardial infarction.[4,5] Echocardiogram and chest computed tomography (CT) scan are pivotal to reach a correct final diagnosis. We present a case of a patient with lung cancer, very large myocardial metastasis, and right pulmonary artery stenosis caused by malignant extrinsic compression.

CASE REPORT

A 75-year-old female patient was admitted to our clinic for asthenia and dyspnea. The patient suffered from systemic hypertension and smoked 20 cigarettes/day for 35 years. A chest CT scan identified a considerable formation (54 mm × 52 mm) in the right upper lobe, suspicious of neoplasia. A preoperative evaluation for percutaneous biopsy and lobectomy was performed. Electrocardiogram (ECG) showed sinus tachycardia with right bundle branch block; blood count, creatinine, electrolytes, inflammation indices, troponin, and B-type natriuretic peptide were within normal limits. Transthoracic echocardiography, despite suboptimal acoustic windows, showed normal global kinesis and no regional wall motion abnormalities, along with concentric hypertrophy of the left ventricular. The right ventricle was slightly distended, and a large pedunculated mass was observed within the ventricular cavity. The lesion, originating from the apical endocardium, had mixed echogenicity and clear margins (20 mm × 34 mm × 12 mm) [Figure 1a and b]. In addition, there were indirect signs of high probability of pulmonary hypertension (Tricuspid regurgitation velocity [TRV] 3.4 m/s, pulmonary artery pressures 50 mmHg). The lesion was suspected a metastasis or primary cardiac tumor or pulmonary embolism. A chest CT scan with contrast medium was requested to clarify the differential diagnosis, and it showed compression by the lung mass on the upper lobar bronchus and the trunk of the right pulmonary artery and no signs of pulmonary embolism [Figure 2a and b]. Therefore, pulmonary hypertension was suspected to be caused by extrinsic compression of the right pulmonary artery. In addition, the contrast medium showed a pedunculated mass inside the right ventricular cavity. The radioactive tracer of positron emission tomography-CT was collected from the right lung lesion, many other small lesions (contralateral lung, bones, and retroperitoneum), and the right ventricular mass [Figure 3a and b]. A transthoracic biopsy confirmed the diagnosis of lung adenocarcinoma. The case underwent a multidisciplinary team discussion involving a cardiologist, radiologist, oncologist, radiation oncologist, thoracic surgeon, and cardiothoracic surgeon. Due to the patient’s clinical conditions, fragility, and oncological presentation, conducting a transesophageal echocardiogram or tissue characterization with cardiac magnetic resonance imaging was not feasible. While these diagnostic tests would have undoubtedly provided additional diagnostic information, they would have also extended the time required to initiate chemotherapy. Moreover, the localization and extent of the mass had already been determined through multimodality imaging. Consequently, the patient promptly commenced chemotherapy treatment without delays. After a few weeks of treatment, the patient returned to the emergency room again due to dyspnea and syncope. The diagnosis was high-risk pulmonary embolism, progressing to cardiac arrest, subjected to rescue thrombolysis as per the current guidelines,[6] but without success, the patient died.

Figure 1.

(a)The image on the left shows an off-axis four-chamber image. A pedunculated mass inside the right ventricular cavity adhering to the right ventricular free wall can be seen (*). (b) The image on the right shows the details of these masses (*)

Figure 2.

(a) Chest computed tomography scan with contrast medium showed compression by the lung mass on the upper lobar bronchus and the trunk of the right pulmonary artery (*). (b) It also confirms the pedunculated mass inside the right ventricular cavity

Figure 3.

(a) Trasversal view, (b) Sagittal view. The radioactive tracer of positron emission tomography-computed tomography was collected from the right lung lesion, many other small lesions (contralateral lung, bones, and retroperitoneum), and the right ventricular mass (green arrow)

DISCUSSION

Cardiac metastases from other solid tumors are rarely detected and represent an advanced oncological disease. Metastases are present in the pericardium and myocardium, may be localized or diffuse, and the main mechanism for involvement is direct invasion, followed by retrograde lymphatic extensions, hematogenous seeding, and transvenous infiltration. Pericardial metastases often cause pericardial effusion and rarely cardiac tamponade. Myocardial metastases usually are asymptomatic, in fact are revealed in 30% of patients with fatal lung cancer at autopsy, and it is very difficult to diagnose before death because can be asymptomatic in most cases, especially if they are small.[7] In some cases, intrathoracic tumors crush nearby organs. In fact, in our patient, pulmonary hypertension was caused by stenosis with extrinsic compression of the right pulmonary artery. Similar cases are reported in the literature, where occasionally percutaneous stenting has been performed to expand the crushed vessel.[8] Sometimes, cardiac masses cause arrhythmias, low voltage, and nonspecific electrocardiographic alterations. Atrial metastatic infiltration may lead to the development of supraventricular tachyarrhythmias,[9] while infiltration of the His bundle branches may result in branch conduction delays. Our patient had a right bundle branch block; however, a previous ECG was unavailable for comparison. Metastases very rarely reach considerable dimensions; individual nodules may range from 1–2 mm to >2 cm in diameter[2] and often may be an expression of advanced stage or direct invasion, as frequently occurs with lung cancer. Furthermore, larger metastases are often found in the left ventricle, occasionally reaching substantial dimensions.[10] The size of the reported right ventricular cardiac metastasis is exceptionally large, as confirmed by multimodal imaging, and to the best of our knowledge, such dimensions have not been documented previously. The lung adenocarcinoma likely spread early through the bloodstream, allowing a significant intraventricular mass to develop, as would be also confirmed by the smaller size of other secondary lesions. The cardiac mass did not cause heart failure, valve defects, or arrhythmia, despite its large size. The intraventricular mass could undergo embolization in the pulmonary circulatory stream, with a high mortality rate, since the thrombolytic treatment is not effective.

CONCLUSION

The incidence of cardiac involvement is likely underestimated in the clinical setting. This case report shows the importance of cardiovascular screening in cancer patients and the utility of multimodality imaging to identify complications and apply proper guideline-based management in such patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.