Although lymphoma is most common between 30 and 40 years of age, is it the second most common anterior mediastinal mass in children. In adults, the nodular sclerosing form of Hodgkin's disease accounts for most of the lymphomas seen. When confined to the anterior mediastinum, lymphoma may be asymptomatic or present with cough, chest pain or less commonly with mass effect on, or invasion into, adjacent structures. Radiographically, primary mediastinal lymphoma look much like the other anterior mediastinal masses. However, secondary signs, such as pleural effusion or erosion of the sternum are common in Hodgkin's disease while rare in the other masses.
Calcification is rare.
Computed tomography has proven useful in that it often will show that the apparently solid masses seen on plain film is actually composed of enlarged matted lymph nodes separated by well defined interfaces. Resection is not necessary, however, thoracotomy or mediastinoscopy are usually required to confirm the diagnosis. Chemotherapy or radiation are the common modes of treatment. Prognosis varies with the histology. The majority of mediastinal thyroid tissue is a substernal extension of a cervical goiter.