What are the differences between benign & malignant tumours?

Dr Karin Oien introduces the role of pathology in cancer, and describes the difference between benign and malignant tumours.

The word tumour literally means "a swelling." But tumour is often used to mean the same as neoplasia. The word neoplasia literally means "new growth."

According to the pathologist Rupert Willis, writing a century ago, a tumour is "an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the change." Further definitions add that a tumour "is formed by an excessive, uncontrolled proliferation of cells as a result of an irreversible genetic change which is passed from one tumour cell to its progeny."

So a tumour is caused by genetic changes in DNA, which can be inherited. But how can we predict what will happen for the patient? The first way of classifying tumours is by their likely behaviour into benign and malignant. Malignant tumours are what is meant by the word "cancer." So what are benign and malignant tumours? How do we tell them apart? And why is it important?

[fanclub]

ERCP shows a round shaped tumor blocking the bile pass. So a stint was used. Surgeon told its benign. But by seeing the round shaped tumor the gastro surgeon is saying its cancer and not ready to listen about benign structure. Sample gone for biopsy. Age 71. Kindly advise

[MrKawaiiKing]

What if the begin tumor keeps growing and another begin tumor is froming in another spot?

[piratesofphysics]

My mother have some tumors at the sub-scapular region and recently it hurts. We did a FNAC test and found that these tumors are benign. Doctor gave some medicine. But after some days of FNAC test my mother get fever every afternoon. I suspect it is because of cancer. Please give me some opinion. I am very concerned.