Glossary term:


An abnormal lump made out of fatty tissue. Lipomas are commonly found in the normal fat layer under the skin, the layer referred to as “subcutaneous fat”. They are also sometimes found inside the brain or the spinal canal, as congenital abnormalities. This is an abnormal state of affairs because fat is not normally found in these sites. The explanation lies in the embryonic development of the central nervous system. When the neural tube forms it detaches from the overlying layer of tissue, known as the ectoderm. The ectoderm is destined to develop into the skin, as well as the hair, the nails and the teeth. If a small piece of embryonic ectoderm is carried into deeper layers of the developing body, along with the neural tube, it develops into a piece of skin-like material, within the brain or the spine This may be fatty tissue or other skin-derived abnormalities such as dermoid tumours.