These neoplasms are usually located in the anterior mediastinum and are usually discovered during a routine chest x-ray. Symptoms can include cough, difficulty with swallowing, tightness of the chest, chest pain, and shortness of breath, although nonspecific symptoms may occur. These tumors generally are slow growing but are potentially invasive, with metastases to distant organs or lymph nodes. Staging is related to invasiveness.
Surgery is performed with the goal of a complete resection and is the mainstay of therapy.
Radiation therapy is used in patients with invasive thymoma or thymic carcinoma.
Chemotherapy is usually reserved for patients with advanced-stage disease who have not responded to radiation therapy or corticosteroids. Agents that have been effective include doxorubicin, cyclophosphamide, etoposide, cisplatin, ifosfamide, and vincristine.[65,69,72,73,74,75] Responses to regimens containing combinations of some of these agents have ranged from 26% to 100% and survival rates have been as high as 50%.[75,76] Response rates are lower for patients with thymic carcinoma, but 2-year survival rates have been reported to be as high as 50%.
Sunitinib has yielded clinical responses in four patients with adult thymic carcinoma.
The most common primary tumors of the heart are benign. In adults, myxoma is the most common tumor; however, these tumors are rare in children. The most common primary benign heart tumors in children are rhabdomyomas, myxomas, teratomas, and fibromas.[80,81,82] Other benign tumors include histiocytoid cardiomyopathy tumors, hemangiomas, and neurofibromas (i.e., tumors of the nerves that innervate the muscles).[80,83,84,85,86]
Myxomas are the most common noncutaneous finding in Carney complex, a rare syndrome characterized by lentigines, cardiac myxomas or other myxoid fibromas, and endocrine abnormalities.[87,88,89] A mutation of the PRKAR1A gene is noted in more than 90% of the cases of Carney complex.[87,90]
Primary malignant pediatric heart tumors are rare but may include malignant teratomas, rhabdomyosarcomas, chondrosarcomas, infantile fibrosarcoma, and other sarcomas.[80,91]
Secondary tumors of the heart include metastatic spread of rhabdomyosarcoma, melanoma, leukemia, and carcinoma of other sites.
The distribution of cardiac tumors in the fetal and neonatal period is different, with more benign teratomas occurring. Multiple cardiac tumors noted in the fetal or neonatal period are highly associated with a diagnosis of tuberous sclerosis. A retrospective review of 94 patients with cardiac tumors detected by prenatal or neonatal echocardiography showed that 68% of the patients exhibited features of tuberous sclerosis. In another study, 79% (15 out of 19) of patients with rhabdomyomas discovered prenatally had tuberous sclerosis, while 96% of those diagnosed postnatally had tuberous sclerosis. Most rhabdomyomas, whether diagnosed prenatally or postnatally, will spontaneously regress.