Treatment options for esophageal carcinoma include either external-beam intracavitary radiation therapy or chemotherapy agents commonly used to treat carcinomas: platinum derivatives, paclitaxel, and etoposide. Prognosis generally is poor for this cancer, which rarely can be completely resected. (Refer to the PDQ summary on adult Esophageal Cancer Treatment for more information.)
Thymoma and Thymic Carcinoma
A cancer of the thymus is not considered a thymoma or a thymic carcinoma unless there are neoplastic changes of the epithelial cells that cover the organ.[54,55,56] The term thymoma is customarily used to describe neoplasms that show no overt atypia of the epithelial component. Thymic carcinomas have a higher incidence of capsular invasion and metastases. A thymic epithelial tumor that exhibits clear-cut cytologic atypia and histologic features no longer specific to the thymus is known as thymic carcinoma, also known as type C thymoma. Other tumors that involve the thymus gland include lymphomas, germ cell tumors, carcinomas, carcinoids, and thymomas. Hodgkin lymphoma and non-Hodgkin lymphoma may also involve the thymus and must be differentiated from true thymomas and thymic carcinomas.
Thymoma and thymic carcinomas are very rare in children.[57,58] Various diseases and syndromes are associated with thymoma, including myasthenia gravis, polymyositis, systemic lupus erythematosus, rheumatoid arthritis, thyroiditis, Isaacs syndrome or neuromyotonia (continuous muscle stiffness resulting from persistent muscle activity as a consequence of antibodies against voltage-gated potassium channels), and pure red-cell aplasia.[59,60] Endocrine (hormonal) disorders including hyperthyroidism, Addison disease, and panhypopituitarism can also be associated with a diagnosis of thymoma.
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, though 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, and 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.[56,61,62,63,64] 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%.[64,65] Response rates are lower for patients with thymic carcinoma, but 2-year survival rates have been reported to be as high as 50%.
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 heart tumors in children are rhabdomyomas and fibromas.[68,69,70] Other benign tumors include myxomas (as noted above), histiocytoid cardiomyopathy tumors, teratomas, hemangiomas, and neurofibromas (i.e., tumors of the nerves that innervate the muscles).[68,70,71,72,73] 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.[74,75,76] A mutation of the PRKAR1A gene is noted in more than 90% of the cases.[74,77] Primary malignant pediatric heart tumors are rare but may include malignant teratomas, rhabdomyosarcomas, chondrosarcomas, infantile fibrosarcoma, and other sarcomas.[68,78]