Cancer types

Thymoma and thymic carcinoma

Thymoma and thymic carcinoma.

- The thymus is a small gland in the front of the chest, behind the breastbone. It helps the immune system develop in childhood and shrinks in adults.
- Thymic tumours are rare. They are often found on a chest X-ray or CT done for another reason, or because of cough, chest pain, or swelling of the face and neck.
- Sometimes they are found because of a related condition such as myasthenia gravis.
Tap a type on the map.

Why this matters: thymoma and thymic carcinoma behave very differently and are treated differently.
- - The most common type. Usually grows slowly.
  - Divided into subtypes A, AB, B1, B2 and B3. Types A and AB grow most slowly; B3 is the most likely to spread.
  - Often linked to immune conditions such as myasthenia gravis.
  - Can come back many years after surgery, so long follow-up is needed.
- - Less common, grows faster and more often spreads.
  - Rarely linked to myasthenia gravis.
  - Often needs chemotherapy and radiotherapy in addition to surgery.
- Myasthenia gravis (in about 1 in 3 patients with thymoma): muscle weakness that gets worse with use, drooping eyelids, double vision, difficulty swallowing or speaking.
- Less common: low red blood cells (pure red cell aplasia), low antibodies causing repeated infections, and other autoimmune conditions.
- Myasthenia must be checked and controlled before surgery, because anaesthesia can make it worse.
- Some medicines (certain antibiotics, and immunotherapy) can make myasthenia worse. Always tell any doctor that you have a thymoma or myasthenia.

- CT or MRI of the chest shows the size of the tumour and whether it is growing into nearby organs.
- PET-CT is used mainly for thymic carcinoma, to check for spread.
- If the scan strongly suggests a thymoma that can be fully removed, the surgeon may remove it directly without a biopsy first.
- If it is large, growing into nearby organs, or may be another condition (such as lymphoma), a needle biopsy is done first.
- Acetylcholine receptor antibodies: to check for myasthenia gravis, even if there are no symptoms.
- Blood counts and antibody levels: to check for related conditions.

Before starting chemotherapy, immunotherapy or targeted therapy, these tests check that you are fit for treatment, and give a starting point to compare with later.

Test	Why it is done
CBC (complete blood count)	Haemoglobin, white cells and platelets. Treatment can lower them.
RFT (kidney function)	Many medicines are cleared by the kidneys; the dose may need to change.
LFT (liver function)	Many medicines are processed by the liver.
Viral markers: HBsAg, anti-HCV, HIV	Hepatitis B can flare up during treatment. If positive, a tablet is given to prevent this.
Blood sugar (and HbA1c if diabetic)	Steroids given with chemotherapy can raise blood sugar.
ECG and 2D Echo	Check the heart rhythm and pumping before treatment, as some medicines affect the heart.

Before immunotherapy, also:

Test	Why it is done
Serum TSH (thyroid)	Immunotherapy can affect the thyroid gland.
Serum cortisol (morning sample)	Immunotherapy can affect the adrenal and pituitary glands.

Sometimes needed, depending on your treatment:

Pregnancy test for women who could be pregnant.
Calcium and magnesium: for example before cisplatin or bone-strengthening injections.
Dental check-up before bone-strengthening injections (zoledronic acid or denosumab), as they can rarely affect the jaw bone.
Hearing test before cisplatin, in some patients.
Clotting tests (PT/INR) before a biopsy or chemoport.

Your doctor will choose the tests that apply to you. Some of them are repeated during treatment.

The stage (often written as Masaoka-Koga stage) tells how far the tumour has grown. Tap your stage on the map.
Treatment depends on the type and stage, and is planned by the tumour board (surgeon, radiation and medical oncologist). Tap your stage on the map.
- 1. Surgery to remove the whole thymus and the tumour (thymectomy). Complete removal is the most important factor for cure.
  2. Radiotherapy after surgery for some patients: for example stage 2 with a higher-risk subtype, thymic carcinoma, or if the edges are not clear.
  Side effects: surgery · radiotherapy
- 1. If the tumour can be removed: surgery, then radiotherapy.
  2. If it cannot be removed safely at first: chemotherapy first to shrink it, then surgery if possible, then radiotherapy. If surgery is still not possible, radiotherapy with or without chemotherapy.
  Side effects: chemotherapy · surgery · radiotherapy
- 1. Chemotherapy: for thymoma, often cisplatin, doxorubicin and cyclophosphamide (CAP); for thymic carcinoma, carboplatin with paclitaxel.
  2. Surgery can still help some patients with limited spread to the lining of the lung.
  3. Later options: lenvatinib or sunitinib tablets for thymic carcinoma; octreotide injections (sometimes with steroids) for some thymomas.
  4. Immunotherapy is used cautiously, mainly for thymic carcinoma, because it can cause serious immune side effects (including heart and muscle inflammation), especially in thymoma.
  What the research shows
  - REMORA: lenvatinib controlled thymic carcinoma in many patients after chemotherapy.
  Side effects: chemotherapy
Tap a treatment on the map. Most side effects can be prevented or managed.
- - Chest pain and tiredness for a few weeks. Often done by keyhole or robotic surgery, which speeds recovery.
  - If you have myasthenia, it is closely watched around the time of surgery.
- - Tiredness, and a sore or difficult swallow during the later weeks.
  - Rarely, months later, inflammation of the lung (cough, breathlessness). Report it.
- - Hair loss, nausea, tiredness and low blood counts. Fever of 38°C or more needs urgent care.
  - Doxorubicin can affect the heart: an echo is done before treatment.
  More about chemotherapy · Side effects of your regimen
- Long follow-up: thymoma can come back many years later. A CT scan every 6 months for 2 years, then every year for at least 10 years.
- Myasthenia warning signs (difficulty breathing or swallowing) need emergency care.
- Always tell any doctor or dentist that you have a thymoma or myasthenia before starting new medicines.
- When to seek help urgently

This information is general. Your own treatment plan may be different. Please discuss it with your doctor.

Written and medically reviewed by Dr Prathyusha Eaga, MD, DM (Medical Oncology). Last reviewed: 12 October 2026. Based on NCCN and ESMO guidelines.

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