Primary cardiac metastatic angiosarcoma

Clinical History

A 62-year-old male patient was referred to our hospital with the diagnosis of cutaneous metastases of angiosarcoma of unknown origin and a mass in the right atrium visualized by echocardiography, in order to inquire the primary lesion and evaluate the extension.

Imaging Findings

The patient underwent cardiac MRI that revealed an intracardiac mass of 5.5 cm x 5.6 cm connected to the posterolateral wall of the right atrium, which appears to be infiltrated, with signs of extra-auricular extension. The mass extended from the lateral margin of the inferior vena cava (IVC) to the superior vena cava (SVC), through the crista terminalis. It was hyperintense in black blood sequences compared to myocardium and with focal areas of hyperintensity in SSFP sequence, probably corresponding with necrosis or cystic degeneration.
The thoracic-abdominal CT showed multiple nodular liver and splenic lesions, as well as osteolytic lesions in the axial skeleton, suggestive of metastases.

Discussion

Cardiac angiosarcoma (CA) is an aggressive infiltrative lesion that originates from mesenchymal angioblast [1]. It is the most frequent primary malignant cardiac tumour, accounting for 37% of all cardiac malignancies [2, 3, 4].
CA is commonly found in middle-aged patients with a peak of incidence in the fourth decade and male predominance. 75% of cases of CA are located in the right atrium, opposite to other primary cardiac sarcomas. The pericardium is frequently involved [2, 5, 6]. It can also invade adjacent structures such as the superior or inferior vena cava, tricuspid valve, right ventricle and right coronary artery [1]. The diagnosis is made usually late in the course of the disease with distant metastases, most often in the mediastinal lymph nodes, lung, liver and bone [1, 2, 5, 6].

Clinical symptoms are nonspecific and usually secondary to right heart failure and tamponade, because of their tendency to occur in the right atrium and to invade the pericardium. When clinical symptoms appear, the tumour is usually at an unresectable stage. Even when the tumour has invaded the pericardium, pericardiocentesis yields bloody fluid often without malignant cells [3].

New imaging techniques have improved CA detection.
The widely available echocardiography can precisely locate and define the tumour extension, especially transoesophageal echocardiography, which has 97% sensitivity in detecting cardiac masses [5]. The location, shape, size, attachment and mobility of the tumour are better assessed by transthoracic echocardiography [5].
CT and MRI have the advantage of showing the extracardiac extent of the tumour and presence of metastases in addition to the anatomical details of the lesion.
At CT, two morphologic types have been described in CA: a well-defined heterogeneous mass protruding into a cardiac chamber, often of low attenuation, irregular or nodular, which may present haemorrhage or necrosis [3, 6] or a diffusely infiltrative mass extending along the pericardium.
MRI is the modality of choice for evaluating abnormalities of the myocardium and can provide functional information. It demonstrates a heterogeneous signal intensity mass, predominantly hyperintense in T2WI and isointense to myocardium in T1WI, with areas of high signal intensity corresponding to haemorrhage [1].

Complete surgical excision is the only treatment that has been shown to prolong survival. The role of adjuvant chemotherapy remains undefined and radiotherapy use is limited by the poor tolerance of the heart. Regardless the treatment chosen, survival ranges from 6 to 12 months. [7, 8, 9].

Differential Diagnosis List

Final Diagnosis

Primary cardiac metastatic angiosarcoma.

URL:	https://www.eurorad.org/case/12859
DOI:	10.1594/EURORAD/CASE.12859
ISSN:	1563-4086