What is a solid tumour?

Author: Gesche Tallen, MD, PhD, erstellt 2003/12/11, Editor: Dr. med. Gesche Tallen, Reviewer: Prof. Dr. med. Dr. h. c. Günter Henze, English Translation: Hannah McRae, Last modification: 2013/05/23

The term "tumour" originiates from Latin and means "swelling" or "lump". The term does not include any information on the characteristics of the lump. It just describes a firm or substantial (solid), locally circumscribed increase of mature or immature tissue of the body. Sometimes, this tissue may be as immature as it is in an unborn child (embryo or fetus).

In professional medical terminology, the term describing a specific tumour usually ends with "oma", while the first part indicates the tissue type of origin. For example, "lipoma" is a tumour consisting of fat tissue, and an "osteoma" is a bone tumour.

Solid tumours can be benign or malignant (cancer):

Benign tumours are not cancer! They usually grow slowly, do not invade adjacent tissue or organs, and do not spread to distant sites (metastasis). Benign tumours sometimes disappear by themselves without any treatment. They can also show spontaneous growth arrest. Some tumours are of borderline malignancy. They may modify their behaviour as they grow, which means that they can, under certain conditions (which are still being identified by childhood cancer researchers), acquire the capacity to invade and spread, and thus become malignant.

Malignant solid tumours are cancerous. That part of the malignancy that has been identified at the tumour's origin is called "the primary tumour", while the tumour's spread to other sites of the body is called metastasis.

Both the form and the properties of a solid tumour or a cancer, respectively, have to be thoroughly assessed (classified) prior to any treatment. This requires specific tests for each disease.