## 9 Cardiac Tumors  
HIV-infected individuals have a higher risk of developing malignancy through different pathogenic pathways: immunosuppression, direct effects of the virus, coinfection with other oncogenic viruses (Ebstein-Barr virus, Hepatitis B and C viruses, human papillomavirus, etc.), or increased sensitivity to environmental factors like tobacco. There is also a possible link between HAART and some cancers [65]. Cardiac neoplasms are generally a manifestation of metastatic disease. Heart malignancy has been found in 28% of HIV-infected patients, most necropsy cases being Kaposi's sarcomas, and is relatively rarely described as a primary heart tumor. The primary involvement of the heart associated with HIV is mainly due to lymphomas--in 1990, non-Hodgkin lymphoma (NHL) became an HIV-defining condition. Non-Hodgkin lymphomas are estimated to have a 25-60-fold higher incidence in HIV-infected people and are the first manifestation of the disease in over 3-4% of new cases, with a marked decline in the era of HAART. Multiple risk factors have been identified in the development of non-Hodgkin lymphoma.  
In 1983, Autran described the first case of cardiac Kaposi's sarcoma in a patient with HIV infection [66]. On retrospective necropsy, the incidence of cardiac Kaposi's sarcoma was 12-28% [67]. The disease affects the visceral sheet of the pericardial serosa or the subepicardial adipose tissue. There is a predilection for Kaposi's sarcoma to affect the subepicardial fat adjacent to a major coronary artery, with or without the involvement of the ascending aorta or pulmonary artery trunk.  
In 1985, the US Centers for Disease Control and Prevention recognized the link between intermediate and high-grade lymphomas and HIV-positive people and included them in the diagnostic criteria for AIDS.  
Malignant lymphomas are not very common in AIDS, but they are the second most frequent neoplasm affecting the heart [68]. Lymphoma infiltration may be diffuse or may be organized as discrete isolated lesions, usually derived from Burkitt cells or B-type immunohistochemical cells. Cardiac lymphoma--the disseminated form--is more common than the primary cardiac form. It is estimated to be responsible for 15% of all cardiac and pericardial metastases in HIV-infected patients. The HIV immune impairment is considered to be the primary mechanism, with patients having high HIV-RNA viral loads, together with CD4 of less than 110 cells/\(\mu\)L [69]. Primitive cardiac lymphoma is extremely rare; patients usually have nonspecific symptoms, but after their onset, heart failure progresses rapidly. At the time of detection, patients may present with refractory heart failure, pericarditis, cardiac tamponade, or cardiac arrhythmias [70; 71].  
The most common tumor presentation is in the form of polypoid or nodular masses that mainly affect the pericardium, with varying degrees of myocardial infiltration [72]. From a histological point of view, they are diffuse, aggressive forms of lymphoma, generally with small, undifferentiated, or immunohistochemical cells [73; 74]. Patients with mechanical obstructive forms may benefit from surgical resection. The prognosis of patients with HIV-associated cardiac lymphoma is usually poor, although cases of clinical remission have also been reported after combined chemotherapy. Even though the heart can be considered a primary lymphoma site, in many HIV patients, the cardiac involvement usually represents a metastatic process.