{'fraction_non_alphanumeric': 0.022585128561501043, 'fraction_numerical': 0.007644197359277276, 'mean_word_length': 5.369469026548672, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Primary Epithelioid Hemangioendothelioma of the Heart

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor characterized by capillary-sized vessels lined by rounded and multilayered endothelial cells. EHE can be found in soft tissues, bones, mediastinum, and many organs such as liver, skin, central nervous system, pleura, and lung.1 Cardiac EHE is extremely rare and considered a lowgrade sarcoma in the latest edition of the World Health Organization classification of cardiac tumors. However, it has a favorable outcome after surgical resection, even in the rare cases of pulmonary metastasis.2 EHEmust be regarded as a malignant neoplasm with local aggressiveness and metastatic potential; thus, requiring radical resection to prevent metastatic spread and improve life expectancy and quality of life.2 For this reason, surgical excision plays a crucial role in the management of EHE but may be a challenging procedure in cases of cardiac localization. Cardiac ultrasound in a 56-year-old man with a history of sinus pauses disclosed a reduced ejection fraction of 47 per cent and an intrapericardial mass. Subsequent cardiac CT and MRI showed the lesion infiltrating the common trunk of the pulmonary artery and the outflow tract of the right ventricle (Fig. 1). A Holter electrocardiogram disclosed a six-second pause. After hospital admission, a further electrocardiogram recorded a 14-second systolic pause requiring leadless pacemaker implantation. Two CT-guided needle biopsies of the lesion were attempted to obtain a histological diagnosis, but both were unsuccessful. A decision was taken to resect the mass; after median sternotomy and pericardium opening, surgical exploration confirmed that the pulmonary artery common trunk and the outflow tract of the right ventricle were infiltrated by the mass. Cardiopulmonary bypass was then started and the mass was radically resected. The cardiovascular defect was repaired by autologous pericardial patch (Fig. 2). On gross examination, the tumor was composed of a parenchymatous yellow-reddish mass measuring 4 cm in greatest diameter. Histopathology revealed a multicellular infiltrating tumor with a predominantly epithelioid morphology, without pleomorphism or mitotic figures. The tumor displayed immunoreactivity to CD31, ERG, and factor VIII and negativity to anticytokeratin staining. The postoperative course was uneventful. In view of the radical resection, the absence of synchronous metastases and tumor indolence documented by stable CT findings during the preoperative six-month period, chemotherapy was not suggested and twice yearly chest CT scan follow-up was started. Primary cardiac tumors are rare, with incidences ranging from 0.001 to 0.2 per cent in autopsy series. The vast majority of primary tumors are benign, about half them being myxomas; around 25 per cent are malignant, most