C37: Malignant neoplasm of thymus

You have cancer in your thymus gland.

The tissue in the body is made up of cells. With cancer, the cells multiply uncontrollably, which leads to a malignant neoplasm (abnormal growth of tissue) developing. The cancer cells can destroy the healthy tissue and spread throughout the body.

The thymus gland is a small organ which forms part of the immune system. The thymus gland lies below the neck and is partly surrounded by the lungs. Immune cells mature in the thymus gland. The thymus gland is at its largest in children and adolescents. Later in life, the thymus gland gradually shrinks since it is no longer required.

The cells in your thymus gland have multiplied uncontrollably.

Please note: This ICD code may also derive from the ICD-O system. If this is the case, there are usually additional letters and numbers in addition to the code. It starts with the letter M, followed by 4 digits and then a slash. There is another digit after the slash.

If it is an ICD-O code, then this does not describe a malignant cancer in all cases. The last digit after the slash gives you more detailed information about this:

• /0 – The tumor is benign. Cells in a tissue multiply uncontrollably. However, they are not destroying the surrounding tissue and are also not spreading throughout the body.
• /1 – It is not known for sure whether the tumor is benign or malignant.
• /2 – It is an early form of cancer, a precancerous stage where the cells are altered and multiply uncontrollably. However, they are not yet spreading beyond a certain margin and cannot spread to other organs either.
• /3 – It is a malignant cancer. The cells in the affected tissue are altered and multiply uncontrollably. They can destroy the surrounding tissue and spread throughout the body.
• /6 – It is a metastasis. Cancer cells have spread from the originally affected site to a different site in the body and have further multiplied there.
• /9 – It is either a malignant cancer or a metastasis. The cells in the affected tissue are altered and multiply uncontrollably. However, it is impossible to say whether these cells derive originally from the affected site or have spread there from a different site in the body.