Tumours are abnormal growths in your body. Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells as you need them, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should. These extra cells can form a mass called a tumour. Tumours can be benign or malignant. Benign tumours aren't cancer while malignant ones are. Cells from malignant tumours can invade nearby tissues. They can also break away and spread to other parts of the body.
Also called: Benign cancer, Benign neoplasms, Noncancerous tumours
Benign tumours are not cancer:
• Benign tumours are rarely life-threatening.
• Generally, benign tumours can be removed, and they usually do not grow back.
• Cells from benign tumours do not invade the tissues around them.
• Cells from benign tumours do not spread to other parts of the body.
Treatment often involves surgery
Malignant Tumour
Also called: Carcinoma, Malignancy, Neoplasms, Tumour
Malignant tumours are cancer:
• Malignant tumours are generally more serious than benign tumours. They may be life-threatening.
• Malignant tumours often can be removed, but sometimes they grow back.
• Cells from malignant tumours can invade and damage nearby tissues and organs.
• Cells from malignant tumours can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumour and entering the bloodstream or lymphatic system. The cells can invade other organs, forming new tumours that damage these organs. The spread of cancer is called metastasis.
HOWEVER, not all cancers are in the form of tumours. For example, leukaemia is a cancer of the bone marrow and blood.
Difference between benign and malignant tumours
The two important differences between benign and malignant tumours are invasion and spread.
• As they grow benign tumours simply push the surrounding normal tissues and organs out of their way. Sometimes pressure from a benign tumour may damage surrounding structures but the benign tumour never actually invades into those structures. By contrast malignant tumours eat into and destroy the normal tissue around them as they increase in size. This means that in some parts of the body benign tumours can grow quite large without causing any problems whereas a malignant tumour damages the tissue around it from the time it first begins to grow.
• Benign tumours do not spread. They may grow to a large size but they do not go to other parts of the body. Malignant tumours have the ability to spread by sending off seedlings of tumour which can pass through the blood or lymphatic system to other parts of the body. These seedlings then settle in other organs and form what are called secondary tumours or metastases.Whilst all malignant tumours have the ability to spread, different tumours vary in the speed with which they do so.
• The difference between benign and malignant tumours has nothing to do with frequency - in some organs of the body benign tumours are much more common than cancers, nor does it have anything to do with size, some benign tumours can be very large whilst many cancers are quite small.
•The different types of benign and malignant tumours behave in different ways but the fundamental rule that benign tumours never invade or spread always applies
Confirmatory test
• Doctors can tell if a tumour is benign or malignant by examining a small sample of cells under a microscope. This is called a biopsy.
• First, Imaging
• Imaging can be used to find out where a cancer is located in the body, if it has spread, and how much is present. E.g. ultrasound, MRI, or PET/CT CT scans
• Then, Biopsy (removal of a small piece of tissue for lab exmination) / Tissue sampling
E.g. Fine-needle aspiration, Core needle biopsy, Vacuum-assisted biopsy, Image-guided biopsy
How the Test is Performed
There are several different types of biopsies.
A needle (percutaneous) biopsy removes tissue using a hollow tube called a syringe. A needle is passed through the syringe into the area being examined. The surgeon uses the needle to remove the tissue sample. Needle biopsies are often done using x-rays (usually CT scan), which guide the surgeon to the appropriate area.
An open biopsy is a surgery that uses general anesthesia. This means you are asleep and pain-free during the procedure. The procedure is done in a hospital operating room. A surgeon makes a cut into the affected area, and the tissue is removed.
Closed biopsy uses a much smaller surgical cut than open biopsy. A small cut is made so that a camera-like instrument can be inserted. This instrument helps guide the surgeon to the appropriate place to take the sample.
How to know whether the tumour is malignant or benign
The overall size and shape of cancer cells are often abnormal. They may be either smaller or larger than normal cells.
The size and shape of the nucleus of a cancer cell is often abnormal. Cancer cells typically have a nucleus that is larger than that of a normal cell. And, like the overall cell size and shape, the size and shape of the cell nucleus is generally similar among normal cells of each tissue but can vary greatly among cancer cells. Another feature of the nucleus of a cancer cell is that it appears darker when seen under a microscope after being stained with certain dyes. The nucleus from a cancer cell is larger and has a darker shade because it often contains too much DNA.
Cancer cells do not relate to each other normally. Sometimes the cancer cells form abnormal or distorted glands. Sometimes they form cell clumps that do not look like glands at all. Another feature that shows abnormal interactions by cancer cells is that cancer cells invade other tissues. Normal cells stay where they belong within a tissue.
Risks
• Bleeding
• Infection
LINKS
http://www.nlm.nih.gov/medlineplus/cancer.html
http://www.insidecancer.org/
http://www.cancerbackup.org.uk/Aboutcancer/Whatiscancer/Whatiscancer
http://www.nlm.nih.gov/medlineplus/benigntumors.html
www.nlm.nih.gov/medlineplus/ency/article/003416.htm
http://www.mayoclinic.com/health/biopsy/ca00083
http://www.cancer.org/docroot/ped/content/ped_2_3x_testing_biopsy_and_cytology_specimens_for_cancer.asp?sitearea=ped
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