Cancer Institute A national cancer institute
designated cancer center

What are Thymoma and Thymic Cancer

Thymoma is a tumor of the thymus gland or thymic tissue – a small organ located in the upper portion of your chest (also called mediastinum), extending from the base of the throat to the front of the heart. The thymus gland is part of your immune system, and secretes hormones that enable T-Cells (disease-fighting cells) to function against disease-causing organisms. The thymus is most active in children and becomes less active with age, so removal of the thymus has no ill effects in adults.  Most thymomas have a relatively high rate of cure with either surgery alone, or surgery plus radiation therapy.  Some more advanced thymic tumors are categorized as “thymic cancer” rather than as “thymoma.”  These tend to be more aggressive than thymomas, and even if they have not spread beyond the mediastinum, they are often treated with combination therapy, including chemotherapy, radiation, and surgery.

Thymus cancers are rare, accounting for about 0.2% to 1.5% of all cancers, and can be difficult to diagnose.


The thymus has different types of cells, each of which can develop into different types of thymoma or cancer:

Physicians can tell the different thymic cancers apart by how they look under the microscope and by the results of other lab tests done on tissue samples.

Stanford Medicine Resources:

Footer Links: