The difference between benign and malignant tumors is that a benign tumor does not invade its surrounding structures while a malignant tumor invades its surrounding structures.
A tumor is formed when the uncontrolled division of the cells occurs, and a mass appears in the form of a lump which is termed as a tumor. A tumor may be benign or malignant in nature. A benign tumor is that which does not spread beyond its limit and never invades its surrounding structures. While a malignant tumor is that which invades its surrounding structures and spreads in the body at distant places. The spread of a malignant tumor is termed as metastasis.
Histologically, the benign tumor appears similar to the cells of origin while malignant tumors vary ranging from similar to the cells of origin to totally anaplastic (different). Tumor edges of benign tumors grow outward in a smooth fashion and do not infiltrate to surrounding tissues while tumor edges of malignant tumors grow outward in an irregular fashion and infiltrate the surrounding structures.
Tumor cells of benign tumors do not separate from the clone or mass of cells from which they originated. They remain attached with the clone of cells. They do not metastasize elsewhere in the body. While the tumor cells of malignant tumors detach from the clone or mass of cells of their origin and tend to metastasize in the distant places of the body. This tendency of malignant cells is called as metastasis.
The growth rate of benign tumors is slow while the growth rate of malignant tumors is fast.
Benign tumors have slight vascularity. They have a poor blood supply. While malignant tumors have moderate to the rich blood supply and that is the reason they grow rapidly because they are provided with adequate blood supply required for rapid growth.
Necrosis and ulceration do not occur commonly in benign tumors while necrosis and ulceration are common in the malignant type of tumors.
Benign tumors do not affect the systems of the body unless they secrete any hormone which is less common. While metastatic tumors have adverse systemic effects. They spread to the brain, bones, liver, heart, kidney and other distant areas of the body and have adverse effects on their functions.
Benign tumors are usually encapsulated while malignant tumors are not encapsulated. Due to the presence of a capsule, benign tumors are sharply demarcated while malignant tumors are not demarcated due to their invasion of the surrounding tissues.
There is no history of weight loss in the patients suffering from benign tumors while there is remarkable weight loss in the patients who have advanced stage of malignant tumors.
Benign tumors are not further classified according to their staging while malignant tumors are further classified according to TNM classification to understand the degree of their extent.
Benign tumors of hepatocytes are called hepatocellular adenoma while malignant tumors of hepatic cells are called hepatocellular carcinoma.
Benign tumors of squamous cells of the skin are called squamous cell adenoma while malignant cells of squamous cells are called squamous cells carcinoma.
Comparison Chart
| Basis | Benign Tumor | Malignant Tumor |
| Definition | They are the type of tumors that do not invade the surrounding tissues. | They are the types of tumors that invade the surrounding tissues. |
| Growth rate | The rate of growth is slow | The rate of growth is moderate or fast |
| Blood supply | Their blood supply is poor. | Their blood supply is rich. |
| Presence of capsule | They are encapsulated and sharply demarcated from their surroundings. | They are neither encapsulated nor demarcated. |
| History of weight loss | There is no history of weight loss in patients suffering from benign tumors. | There is a history of remarkable weight loss in the advanced stages of malignant tumors. |
| Systemic effects | They have no systemic effects. Rarely they produce hormones, and in this case, they affect systems. | They invade the important organs of the body, and in this way, they adversely affect the systems of the body. |
| Histological appearance | Histologically benign tumors are similar to the cells of their origin. | Histologically they may be similar or completely different from the cells of their origin. |
| Degree of differentiation | They are always well differentiated. | They vary from well-differentiated to completely anaplastic tumors. |
| Separation from clone | They do not separate from their clones or mass of cells. | They separate from a clone of cells and spread to the distant areas in the body. |
| Example of hepatocellular variant | Hepatocellular adenoma. | Hepatocellular carcinoma. |
What are Benign Tumors?
Benign tumors are the types of tumors that are well-differentiated and confined to the site of their origin. They do not infiltrate the surrounding structures. The cells of benign tumors do not separate from the clone of their cells and never spread in the body. That is why they are called as benign (innocent) tumors. Benign tumors are mobile. They have their own capsules, and in case they do not have a capsule, they are sharply demarcated from the surrounding tissues. The cells of benign tumors histologically appear similar to the cells of their origin. The rate of their growth is slow, and they have a poor blood supply. Due to poor vascularity, they are not provided with enough nutrients to grow rapidly, that is the reason their growth rate is very sluggish.
Benign tumors do not affect the systems of the affected person except if they produce any type of hormone. Rarely, benign tumors have glandular elements, and in this case, they produce hormones or neuroendocrine factors that affect the body systems. The treatment of a benign tumor is a simple surgical excision.
Examples of benign tumors can be given as fibroadenoma of breast, hepatocellular adenoma, squamous cell papilloma, myxoma, and schwannoma.
What are Malignant Tumors?
Malignant tumors are the type of tumors that have to potential to invade the surrounding tissues. The degree of their differentiation varies. They may be completely differentiated or completely anaplastic or range in between these two extremes. Malignant tumors do not have a capsule and not demarcated at all from the surrounding tissues. They often have a rich blood supply, and that is the reason their growth rate is high. They have the ability to separate from the clonal cells and invade the distant areas of the body. This property of malignant cells is called metastasis. The treatment of malignant cells (cancer) is done by chemotherapy, radiotherapy or surgery. Examples of malignant tumors are hepatocellular carcinoma and carcinoid tumor.
Key Differences between Benign Tumor and Malignant Tumor
- Benign tumors do not invade the surrounding tissues while malignant tumors invade.
- Benign tumors are encapsulated and sharply demarcated while malignant tumors are not.
- Benign tumors grow slowly and have poor blood supply while malignant tumors grow rapidly and have an abundant blood supply.
- Benign tumors do not have the ability of metastasis while malignant tumors have.
- Benign tumors are completely differentiated while malignant cells are usually undifferentiated.
- Benign tumors are treated by simple surgical excision while malignant tumors are treated by chemotherapy, radiotherapy, and surgery.
Conclusion
Benign and malignant are two kinds of tumors that commonly occur in the general population. Often they are confused with each other, so it is compulsive to know the differences among both of them. In the above article, we learned the clear differences between both types of tumors.