Approach to cardiac masses: Thinking inside and outside the box

Table 2 Simplified World Health Organization classification of heart and pericardial tumors[3]

Group	Histologic type
Benign congenital/childhood	Rhabdomyoma, histiocytoid cardiomyopathy, congenital or childhood fibroma, cystic tumor of the atrioventricular node, hamartomas, germ cell tumors, schwannoma, granular cell tumor
Non-neoplastic tumors of adults	Papillary fibroelastoma, lipomatous hypertrophy of atrial septum
Neoplastic benign tumors	Myxoma, lipoma, hemangioma
Malignant tumors	Angiosarcoma, rhabdomyosarcoma, leiomyosarcoma, osteosarcoma, synovial sarcoma, pericardial malignant mesothelioma, lymphoma
Intermediate behavior	Inflammatory myofibroblastic tumor, low-grade angiosarcoma, infiltrating hemangiomas, cardiac paraganglioma, solitary fibrous tumor of the pericardium, adult cellular rhabdomyoma