Differences between Malignant Tumors and Benign Tumors

What are the Characteristics of Neoplasia?

Neoplasia comprises of both malignant and benign tumors.

What are the differences between Malignant Tumors and Benign Tumors?

Benign neoplasm:

If there are clusters of tumor cells in a single mass, they are called benign tumors. These tumors are not malignant. Benign tambours are not harmful in general, but in very less cases they may result in death if they interfere with the vital functions. The specific name of the cancer end with ‘oma’.

For e.g. Hepatoma is the benign tumor of the liver.

Liver Cirrhosis – Hepatoma d17-1 (Photo credit: Albaraa Mehdar)

Benign tumors show slow growth rate. The tumors are encapsulated. They contain well-differentiated cells and they resemble the tissue of origin. They do not undergo metastasis.

Malignant neoplasm:

Malignant tumors are the tumors that have the ability to undergo metastasis. They break loose and spread to other areas of the body. These tumors are harmful tumors and they may result in death finally if they are left untreated.

Malignant tumors show rapid growth rate. They are non-encapsulated. They do not contain well differentiated cells (undifferentiated).It is known as anaplasia.They show loss of contact inhibition. They readily undergo metastasis. They can express foreign antigens.

Malignant tumors have special properties like dedifferentiation, invasiveness and metastasize. They show abnormal gene expression due to the above special characteristics. The altered gene expression results from genetic mutations. Malignant tumors may invade lymph nodes or distant body sites like brain, bone liver etc.,

Hepatocellular Carcinoma (Photo credit: euthman)

Some of the examples of malignant tumors are:

• Hepatocarcinoma is the malignant tumor of the liver
• Carcinoma is the malignant tumor of the epithelial cell origin
• Sarcoma is the malignant tumor of the skeletal or connective tissue origin
• Lymphoma is the malignant tumor of the lymphatic tissue
• Glioma is the malignant tumor of the glial support cells in the central nervous system

Characteristics to distinguish cancerous cells from normal cells:

1. Uncontrolled proliferation
2. Dedifferentiation and loss of function
3. Invasiveness
4. Metastasis

How does a normal cell turn into a cancer cell?

Genesis of cancer cell:

A normal cell turns into a cancer cell due to one or more mutations in the DNA, which may be inherited or acquired.

e.g. Breast cancer: If a woman has a defective copy of either of the tumor suppressor genes BRCA1 and BRCA2, they have risk of developing breast cancer.