Alternatively, you could have polyps - abnormal tissue growths inside the nose and sinuses, which could be caused by allergies, vitamin deficiencies or an under-active thyroid.

But in 16 per cent of complete moles and 0.5 per cent of partial ones the abnormal tissue embedded in the womb becomes cancerous, grows and spreads.

This may cause a patch of abnormal tissue to arise.

This surgery consists of the excision of abnormal tissue.

If the abnormal tissue or cells can be removed, then the disease can be prevented from developing and causing problems.