Thymoma is a rare form of Thymus Carcinoma and can be characterised as the proliferation of cancer cells, in the thymus gland, an organ in the chest, behind the chest bone. The thymus gland is an integral part of the body’s immune response that synthesises lymphocytes, i.e., white blood cells (T-cells) which in turn protects the body from various external microbial invasions and other viral threats.
main
The thymus gland chiefly consists of two cell types: epithelial cells and lymphocytes; and either or both types can mutate and transform into malignant cells. While mutated lymphocytes lead to Hodgkin or Non-Hodgkin lymphoma, mutation of epithelial cells often causes thymoma and thymic carcinoma.

Also Read: Non-Hodgkin Lymphoma: Causes, Symptoms And Treatment

The thymoma cells are usually slow-growing ones and often don’t metastasize to other parts of the body. In a person afflicted with thymoma, the lymphocytes or T-cells often alienate the other healthy tissues and organs and attack them thinking of them as an external microbial invasion. Although both Thymomas and Thymic carcinomas are thymic epithelial tumours (TETs), Thymomas grow slowly and does not spread outside the thymus whereas Thymic carcinoma are fast-growing ones and often metastasize to other distant organs outside the thymus.

Also Read: Lung Cancer: Causes, Symptoms And Treatment

Causes

Just like any other type of carcinoma, the absolute cause of thymoma is still unknown, but several scientific studies indicate that it primarily arises when there are certain mutations in the genes of the thymus gland cells that trigger them to grow abnormally in size and number without dying on time. This causes the mutated cells to agglomerate leading to the growth of tumorous structures inside the thymus gland. These cancerous tumours can often get loose from the original site and gradually metastasize to other parts of the body via the bloodstream and lymphatic ducts.

Risk Factors

Certain causative factors that increase the chances of developing Thymoma include:

Age: Thymoma is more common in adults between the ages of 40 and 75

Other Conditions: People suffering from Autoimmune paraneoplastic syndromes like Myasthenia gravis, Hypogammaglobulinemia, Pure red cell aplasia, Polymyositis, Rheumatoid arthritis, Lupus erythematosus, Thyroiditis or Sjogren's syndrome are more likely to develop Thymoma

Symptoms

Thymoma doesn’t portray any characteristic signs and symptoms in the earlier stages since they grow slowly. It is often detected at an advanced stage during a routine chest X-ray or other unrelated medical tests and procedures. The common indications include:

  • Persistent cough
  • Chest Pain
  • Cough along with bloody sputum
  • Difficulty in breathing
  • Difficulty in swallowing food and water, such as in dysphagia
  • Sudden weight loss without any known reason
  • Chronic fatigue
  • Dizziness
  • Headaches
  • Loss of appetite
  • Shortness of breath
  • Swelling in your neck, face, arms and hands
  • Visible veins in the upper part of the body

Diagnosis And Treatment

Since the symptoms are rare in the case of thymus cancer, it is strictly advocated to undergo a routine physical examination quarterly or yearly to keep your health in check and avoid unnecessary complications. In case you do notice any of the above-mentioned indications, do consult an oncologist at the earliest. The treating doctor usually does a thorough physical check-up to look for the presence of any lumps, acknowledges the patient’s medical history and conducts the following diagnostics:

  • Chest X-ray
  • Imaging tests like MRI-scan, PET-scan, CT-scan
  • Biopsy of the thymus cells

Staging Of Thymoma

After diagnosing the thymoma, the cancerous cells are staged following the TNM staging system, which is a method of categorising cancer based on its size, extent, and other features.

Stage I:

The cancer cells are limited only within the thymus gland

Stage II:

The cancerous cells spread outside the thymus gland, i.e., into the fatty layer encompassing the thymus or into the peritoneal lining of the chest cavity.

Stage III:

In this stage, the malignant cells have metastasized to the nearby lymph nodes, organs like the chest, the outer lining of the heart, or the blood vessels.

Stage IV:

This is an advanced stage, where the cancerous cells have metastasized to both nearby and distant organs through the lymphatic system.

Treatment

The treatment options usually depend upon the stage, the severity of the cancer and the condition of the patient. The various available treatment options to manage Thymoma and bestow the patient with a healthy life comprise:

  • Surgery
  • Radiation Therapy
  • Chemotherapy
  • Targeted therapy
  • Immunotherapy
  • Clinical Trial
  • Palliative Care