Pathology dictionary -
A hamartoma is a non-cancerous tumour. The tumour cells in a hamartoma look similar to normal cells. However, unlike normal cells, the cells in a hamartoma are disorganized and serve no functional for the organ involved. A hamartoma can be made up of one type of cell or several different types of cells.
A hamartoma can develop anywhere in the body. Hamartomas are more common in these areas of the body:
Gastrointestinal tract (especially the colon).
The type of hamartoma will depend on the area of the body involved. For example, a hamartoma in the brain may be made up of neurons (a normal cell type in the brain) but they are connected in a way that serves no real function.
While hamartomas are not considered cancer, they can still cause damage by compressing nearby structures, such as other organs, nerves, or blood vessels.