What Is Thymoma and Thymic Cancer?

CT scan image of a well-circumscribed, anterior mediastinal thymoma 

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.

Thymomas are malignant tumors that arise in the thymus gland, typically in the anterior mediastinum. Although considered malignant, most thymomas grow slowly and tend to spread only locally, by "seeding" cells into surrounding tissues and spaces such as the pleural space (the space surrounding each lung). There is therefore often a very good chance of curing thymomas by either surgery alone or surgery followed by radiation. We often proceed to remove these localized tumors without even the need for a preliminary biopsy. 

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.

Thymoma and thymic cancer program highlights

Stanford thoracic surgeons evaluate and treat a high volume and wide variety of mediastinal diseases. Since many of these lesions are benign, minimally invasive approaches, which allow for less discomfort and faster recovery, can often be utilized. As in all areas of thoracic surgery, Stanford thoracic surgeons have sub-specialty training in the surgical management of mediastinal tumors and diseases. They have far more experience with these relatively rare diseases than general surgeons and even cardiothoracic surgeons at surrounding community hospitals. For example, in the past year alone, Stanford thoracic surgeons have removed or biopsied 204 mediastinal masses—a very large volume of these cases for a single institution.

  • Weekly multispecialty thoracic tumor board to review complex cases and develop optimal treatment plans
  • Advanced diagnostic capabilities, including combined staging/tumor assessment, PET-CT scan
  • Multispecialty treatment for locally advanced thymoma and thymic cancer
  • Surgical expertise, including doctors with extensive experience performing thymectomy (thymus removal) and minimally invasive thymic surgery for smaller tumors. Complete resection is one of the most important determinants of cure and survival rates in patients with thymic tumors. Our surgeons are experienced in all advanced resection and reconstruction techniques, including superior vena cava reconstruction, required to give the greatest chance of cure for thymic malignancies.
  • Clinical trials of potential new treatments for thymoma

Clinical Trials

Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you have access to the latest, advanced clinical trials.

Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.

Before beginning treatment, ask your doctor about any clinical trials you should consider. Learn more about clinical trials for cancer patients.

Clinical trial eligibility flowcharts

Eligibility flowcharts map clinical trials to specific types of cancers to determine if a participant is eligible for the particular clinical trial. View all thoracic and lung cancer eligibility flowcharts at the Stanford Cancer Institute.

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