In the last few years the frequency of the metastatic heart tumours, which occur more frequently than primary tumours of the heart, has increased [1]. Earlier the low incidence of cardiac cancer was explained by the theory that the heart was not "susceptible" to tumour cells. This theory was supported by several factors: powerful activity of the myocardium, metabolic specifics of cardiac muscle and rapid blood flow through the heart [2]. During the last years the frequency of cardiac metastases has increased due to the patients’ increased life expectancy originating from modern surgical, radio- and chemotherapies. According to literature data cardiac metastases are found in up to 25% post-mortem. The following tumours metastasize to the heart in a decreasing order of frequency: malignant melanoma, lung cancer, breast cancer, esophageal cancer, lymphoma and leukemia [1]. Solitary metastases to the heart are rare, usually it develops in patients having already had a disseminated tumour. The following layers of the heart are affected in a descending order of frequency: pericardium (75.5%), myocardium (38.2%), and endocardium (15.2%). Metastases reach the heart by lymphatic, hematogenous, direct or transvenous pathway through the superior and inferior vena cava [3]. The right side of the heart is more frequently involved than the left side, but metastases to both sides of the heart were observed also. The aim of our case report is to draw attention to the possibility of cardiac metastases through one of our female patients suffering from duplex tumour.

Figure 1. Thickened inferior wall on two-dimensional echocardiography.

A 55 year-old woman was referred to the hospital due to bilateral neck lymph node enlargement. Her examination revealed a cancer of the supraglottis in May 2013. In July 2013 total laryngectomy with resection of the base of the tongue was performed with left side modified and right side radical neck dissection. The histology showed squamosus cell carcinoma (pT3pN2), based on this the patient received postoperative radiotherapy for the tumour bed and its lymphatic drainage in a total dose of 60 Gy. After completing radiotherapy the patient was scheduled for a follow-up visits in every 3 months. In May 2014 she complained of several subcutaneous lumps developed recently on her neck, in the skin of the abdomen and on her back and she noticed slight swelling (lymphedema) in both arms. She got PET/CT examination and one of the subcutaneous lumps was removed. The PET/CT images showed several soft tissue nodules with a maximum diameter of 28 mm in the head and neck region, in the jugular area, in the left supraclavicular and in both axillary regions, on left side of the back, in the lateral area of the right breast, in the right upper arm and around, in the right anterior superior iliac spine and the trochanter major. In addition, numerous well-isolated enhancing lesions 33 mm in their maximal diameter were also revealed in multiple muscles (left deltoid muscle, right supraspinatus muscle, left obturator internus muscle, right major adductor muscle of the hip, left quadriceps femoris muscle), in the basal third of the bottom of the heart focal abnormalities and an intensively enhancing, necrotizing area sized 55x43x45 mm were detected (Figure 1), the latter one could not be separated from the right atrium. In both adrenal glands also metastases were found. The PET/CT identified a nodule sized 16x10 mm in the apex of the right lung. The histology of the removed lump confirmed that it was a metastasis from a squamosus cell carcinoma and based on the dissemination pattern of the tumour lung cancer rather than head and neck cancer was considered as primary. On physical examination, the patient was afebrile with room air oxygen saturation of 96%, she suffered from difficult breathing and her heart frequency was high (110/min) with normal first and second heart sounds with no murmurs, rubs or gallops. Diffuse wheezing was heard over both lungs. Laboratory test showed slight anemia and leukocytosis, all electrolytes were within normal range. The lymphedema of the lower arms worsened compared to the previous findings. An electrocardiogram was performed due to the cardiac lesions detected by PET/CT and the complaints of the patients, it showed sinus tachycardia. The two-dimensional echocardiogram confirmed the mass in the area of the right atrium (which was seen on the PET/CT scans) (Figure 2), it did not intrude the cavity of the atrium, in addition, the basal segment of the heart; no wall motion disorder was detected. The left ventricular ejection fraction was 54%. Beta blocker therapy was introduced to control the tachycardia and based on the disseminated lung cancer status a polychemotherapy consisting of taxol and carboplatin was started. The patient received 3 cycles chemotherapy when the staging examinations revealed multiple osseal metastases and repeated echocardiogramm described the thickening of the inferior wall and the septum, left ventricular ejection fraction remained 54%. In the second line chemotherapy docetaxel monotherapy was started from which she received 2 cycles. The patient died in her home in November 2014.

Figure 2. Increased FDG uptake in the right atrium.

Cardiac metastases usually remain clinically silent, however it should be taken into consideration when during the treatment of a cancer patient dyspnea, tachypnea, systolic heart murmur, peripheral edema, ascites, pleural or pericardial effusion occur [5]. The diagnosis can be set up by several methods such as chest X-ray, which may reveal an increase in cardiac silhouette through pericardial effusion or peri- and/or paracardial tumour growth, two dimensional echocardiography which in case of carcinomas show the diffuse thickening of the pericardium in case of hematological malignancies the diffuse or local thickening of the peri-, myo- or endocardium can be detected [1]. CT or MR scan of the chest could determine the size and the extension of paracardial or transpericardial tumour growth more precisely than sonography [6]. Electrocardiogram can show ventricular or supraventricular arrhytmias, conduction defects, ST segment elevation (pericarditis), low voltage and development of Q wave if the tumour caused myocardial infarction [5]. In case of metastases to the right side of the heart transesophageal echocardiogram can be useful.

Although clinical diagnosis of cardiac metastasis can usually set up by imaging, tissue histology can help to make an exact diagnosis and choose the optimal treatment. Besides exploratory thoracotomy and open biopsy malignant cells can be identified in the majority of malignant pericardial effusions drained by pericardiocentesis. Another approach to more definitively obtain tissue is endomyocardial biopsy. Endomyocardial biopsy is useful especially for right-sided cardiac masses showing infiltration or obstruction.

As cardiac metastases are usually incurable, surgical resection is only indicated with definitive intention when the metastasis is solitary and the patient has a good quality of life, in every other cases it can be indicated as a final, symptoms relieving treatment if the metastases cause tamponade or obliteration of the chamber or valve obstruction [7]. In case of localized metastasis the embolization of the supplying coronary branch may be an option, if complete AV-block pacemaker implantation, and in severe valvular insufficiency valve replacement should be considered. Regarding that the heart metastases represents metastatic tumour stage chemotherapy is a treatment option. Unfortunately the palliative radiotherapy is only effective if the metastases originated from leukemia or lymphoma, in every other cases has no therapeutic effect [1].

In recent years the frequency of cardiac metastases originated from different tumours has increased, mainly due to the cancer patients’ increased life expectancy originating from modern surgical, radio- and chemotherapies, hence metastases can develop in such places where there was not enough time to develop before. Due to the increased number of cases we should be aware of it especially if new heart murmur, dyspne, pericardial fluid or arrhtymia is detected in a patient treated with cancer.