Retrospective study of surgical pathology experience on cardiac and pericardial tumors at the University of Padua in the era of immunohistochemistry and endomyocardial biopsy. In the period 1970-1995, we studied 125 bioptic primary neoplasms: specimens were obtained from surgical resection in 116 cases, heart transplantation in 3, pericardiectomy in 3, endomyocardial biopsy in 2 and thoracoscopic biopsy in 1. Tumor histotype was established by light microscopy and more recently by immuno-histochemistry, using a large panel of antibodies, through avidin-biotin peroxidase method, against factor VIII-related antigen, ulex-europaeus, desmin, myoglobin, muscle-specific actin, smooth muscle-specific actin, vimentin, cytokeratins, leukocytic common antigen, neurofilaments and S100-protein. One hundred and thirteen were benign neoplasms: myxoma was the most frequent (87 cases) followed by pericardial cyst (8), endocardial papilloma (5), fibroma (3), rhabdomyoma (3), hematic cyst (2), teratoma (2), hemangioma (1), celothelioma (1) and lipoma (1). Malignancy was diagnosed in 12 cases, and consisted of pericardial mesothelioma (3), myxosarcoma (3), angiosarcoma (2), fibrosarcoma (2) and leiomyosarcoma (2); 4 of them were intracavitary atrial masses and were supposed to be atrial myxoma on the clinical ground. Differential diagnosis included endocardial thrombosis (10), metastasis of concealed extracardiac tumors (5), echinococcosis (3), and Loeffler's fibroplastic endocarditis (3). In 4 cases, cardiac mass histotype was defined without thoracotomy, through endomyocardial (3) and thoracoscopic (1) biopsy. A large spectrum of cardiac tumors is observed in the surgical pathology practice. Although the diagnosis of cardiac masses is easily attainable by routine imaging techniques, differential diagnosis between primary and secondary tumors, malignant and benign forms, and non neoplastic masses, is achievable only by a thorough microscopic study of surgical resections. The role of the cardiac pathologist is becoming crucial as in other fields of oncology.