Welcome to the Rare Classroom, a new series from Patient Worthy. Rare Classroom is designed for the curious reader who wants to get informed on some of the rarest, most mysterious diseases and conditions. There are thousands of rare diseases out there, but only a very small number of them have viable treatments and regularly make the news. This series is an opportunity to learn the basics about some of the diseases that almost no one hears much about or that we otherwise haven’t been able to report on very often.

Eyes front and ears open. Class is now in session.

The rare disease that we will be learning about today is:

Thymoma

What is Thymoma?

• A thymoma is a tumor which originates from the epithelial cells of the thymus, a lymphoid organ of the immune system.
  • In the thymus, thymus cell lymphocytes, or T-cells, mature​
• This is a rare malignancy that is closely associated with autoimmune and neuromuscular disorders.
  • Thymoma tumors are most often associated with myasthenia gravis, but they can appear alongside many other rare conditions, such as hemolytic uremia, polymyositis, lupus, stiff person syndrome, and many more
  • 10-15 percent of myasthenia gravis patients have a thymoma, and up to 45 percent of people with thymomas have myasthenia gravis
• In rare cases, thymoma can become cancerous and malignant

How Do You Get It?

• The cause of thymoma is not understood
• Men and women seem to be equally likely to develop a thymoma
• There are no known risk factors for this tumor
• Thymomas are most often diagnosed between 30-50 years of age; however, there care thymoma cases recorded from all ages, including children

What Are The Symptoms?

• Up to half of people with a thymoma have no symptoms, and the tumor is often only discovered after the patient has received a CT scan or X-ray for a different health concern.
• However, large thymoma tumors cause symptoms due to compression of the surrounding organs
• These symptoms can include:
  • Chest pain
  • Coughing
  • Difficulty swallowing
  • Superior vena cava syndrome, which causes:
    • Facial swelling
    • Difficulty breathing
    • Headache
    • Neck swelling
    • Distended veins in the chest, arms, and neck
    • Lightheadedness
    • Low lung capacity
  • Autoimmune disorders, like myasthenia gravis

How Is It Treated?

• The primary treatment for thymoma is surgical removal
  • However, if the tumor is large and invasive, treatment with chemotherapy or radiation therapy (sometimes in combination) may be used to shrink the tumor first
• After surgery, no further treatment is necessary in early stage thymomas
  • Surgical removal has no impact on the immune system of adults, but children may have abnormal immune function
  • Children may need additional vaccines against certain infections
  • Additionally, patients of all ages that have had this surgery are at risk of serious side effects and even death following yellow fever vaccination
• Invasive tumors may required additional chemo or radiation treatment
• Invasive thymomas can recur in up to 30 percent of cases up to 10 years after surgery
• Prognosis for stage III or IV thymomas is much worse than earlier stages
  • 10 year survival rate for stage III and IV tumors is 40 percent

Where Can I Learn More???

• Learn more about this disease from the Foundation for Thymic Cancer Research.
• Check out our cornerstone on this disease here.