A thymoma is a type of slow-growing tumour in the thymus gland that usually appears in people in the fourth and fifth decades of life. It is the most common tumour detected in the anterior mediastinum in adults. Up to half of the thymomas are symptomless or not exhibiting any symptoms of the disease. Nonetheless, common symptoms like cough, shortness of breath, and chest pain may be present when symptoms manifest.

Diagnosis is phenomenal when detected in their early stages. Surgeons, not to mention thoracic (chest) surgeons and surgical oncologists, usually treat thymoma. If other treatments indicate an aggressive thymoma or thymic carcinoma,  medical oncologists and radiation oncologists may be involved in the treatment team.

Thymomas are usually benign but may become malignant and spread to other organs such as the lungs. It is not known what causes these tumours to develop. Still, they are associated with various conditions, including myasthenia gravis, where the immune system mounts an attack on multiple muscles in the body. At least 30% of individuals with a thymoma will also have myasthenia gravis. Patients with thymoma may be asymptomatic or may present with symptoms such as chest pain, difficulty breathing or a persistent cough. Once identified by imaging studies or biopsy, treatment usually involves surgery and may also involve radiation therapy to reduce the likelihood of tumour recurrence.


Up to half of the individuals with a thymoma do not experience any symptoms. Symptoms that may occur usually result from compression of surrounding structures.

These symptoms may include chest pain or discomfort, difficulties with breathing and swallowing, a persistent cough, and hoarseness of voice. Besides, symptoms of myasthenia gravis may be present such as muscle weakness, which typically worsens with repeated muscle use and improves with rest. In the rare cases of a malignant tumour, individuals may also experience fever, night sweats, and weight loss.

Some of the symptoms include:

  • Chest pain
  • Cough that doesn’t go away
  • Difficulty in breathing


For patients where a thymoma is suspected based on their symptoms or an established diagnosis of myasthenia gravis, imaging studies of the chest are performed. These include chest X-rays as well as computed tomography (CT) scans of the breast, which provide further detail on the tumour to guide its surgical removal. In some cases, a preoperative biopsy of the suspected tumour may be carried out.


There are different types of treatments available, but surgery to remove the tumour is the first course of medication. Radiation, chemotherapy, and hormone therapy can also be used to treat a thymoma.

Treatment of a thymoma generally involves surgical removal of the thymus gland. This may be carried out by open surgery or minimally invasive methods such as video-assisted or robotic techniques. These minimally invasive techniques may result in less pain and bleeding as well as a shorter length of stay in the hospital compared to open surgery. Additional treatment depends on the extent to which the thymoma has spread to surrounding tissues, which is known as the stage of the tumour. While most cases are benign and require only surgical interventions, invasive tumours usually require postoperative radiotherapy as well to reduce the chance of tumour recurrence.

Tumours that have spread to the lungs and heart may require chemotherapy in addition to surgery and radiation. In most cases of thymoma, appropriate intervention results in a high survival rate. As always, the risks should be weighed against the benefits and discussed with your surgeon.

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