Types of Masses
- Thymoma: The most common anterior mass is a thymoma. There are different types of thymomas. They are generally seen on CT as a round, encapsulated mass, and rarely recur. The larger irregular masses, malignant thymic carcinomas are much more aggressive and have a much worse prognosis.
- Lymphoma: is a cancer that arises in cancer-fighting cells called lymphocytes. Lymphoma usually starts in lymph nodes, the spleen or the bone marrow. Infrequently, lymphoma starts in the anterior mediastinum. There are 2 categories of lymphoma: Hodgkin’s disease and non-Hodgkin’s lymphoma.
- Germ cell: A rare mediastinal mass is a germ cell a tumor. They are very rare. They are usually benign (60 to 70%) and are found in both males and females.
- Thyroid mass: substernal goiter remains a significant consideration in the differential diagnosis of mediastinal masses, particularly those located in the anterior mediastinum. Substernal goiter is generally defined as a thyroid mass that has 50% or more of its volume located below the thoracic inlet.
- Bronchogenic cyst: Bronchogenic cysts are congenital in nature. They are part of a spectrum of congenital abnormalities of the lung, including pulmonary sequestration, congenital cystic adenomatoid malformation, and congenital lobar hyperinflation (emphysema)
- Pericardial cyst: Pericardial cysts are an uncommon benign congenital anomaly in the middle mediastinum. They represent 6% of mediastinal masses, and 33% of mediastinal cysts.
- Neurogenic tumor: The most common cause posterior mediastinal tumors arise from nerves. They are usually benign, especially in adults. They are usually on the side of the backbone.