Tumor vs lesion (The main differences)

In this post we will talk about tumors and lesions, the main types, we will learn the differences between each one and how they are intervened in medicine.

Tumor vs lesion

Brain lesions are any acquired condition or pathology in the brain, whereas tumors are a mass of tissue. Lesions cause cognitive damage while tumors may or may not intervene in cognitive development.

What’s a tumor?

All that foreign tissue that arises within the cavity of the skull is called a brain tumor, although these also sometimes appear in the meninges, nerves and in the skull itself. For obvious reasons, they are one of the main health problems that affect the nervous system, given their potential severity.

In general, brain tumors are more recurrent during childhood, with some tumors being more common to see at this stage of development, such as medulloblastomas. There are also those that occur mainly in adulthood, with meningiomas and schwannomas distinctive of this stage.

Brain tumor symptoms

The symptoms are variable, they depend to a great extent on the size of the tumor, where it is located, and even on the speed it presents with respect to its growth.

The constant headache would be the symptom par excellence in this condition. Other harmful effects would be the following: various cognitive or sensorimotor disorders, increased intracranial pressure that generates vomiting, diplopia (double vision), birth of elipetogenic foci, etc.

Types of brain tumors and classification

Brain tumors can be classified in the following ways:

1. Primary and secondary

Primary ones arise within the brain or spinal cord, and rarely metastasize (spread of the tumor to another part of the body); although it is probable that, as a result of this initial tumor, new ones will arise within the nervous system itself.

The secondary ones are born outside the nervous system and what is known as brain metastasis occurs. That is, it can arise as a consequence of breast, lung, gastrointestinal cancer, etc. It should be noted that this type of tumor is malignant and inoperable.

2. Infiltrators and encapsulates

Infiltrators are distinguished by the fact that there is no limit that establishes where they start and where they end, and in encapsulated ones if it is possible to better distinguish what place it occupies.

Therefore, the former tend to be more dangerous, since as they spread, they tend to deteriorate the area in which they are located.

3. Benign and malignant

There is a scale with various degrees of hierarchy, which allows knowing when they belong to one side and when to the other. Those that are grade are the least harmful (although in the same way they are of considerable danger when they are removed), and those that belong to IV have the worst prognosis.

Generally, tumors that belong to categories I and II do not metastasize, and the survival of those who suffer from them is generally several years; while those that are III and IV if they cause metastasis and survival do not go beyond a few / several months.

Cancer in the nervous system: examples

Here you can see a brief description of various types of tumors that appear in the nervous system.



It is the name given to any tumor that arises from a considerable spread of glia. They are of the evil type.

It is generally caused by an increase in astrocytes (thus generating astrocytomas); in some cases of oligodendrocytes (producing oligodendrocytomas as an effect) and multiform glioblastomas, also known as grade IV gliomas.


This is the name given to tumors of non-glial origin that originate in the meninges, mainly in the subarachnoid space or in the dura mater. They are regularly benign and have a good prognosis.


This is how they are called malignant tumors that very commonly arise in the cerebellum of children due to the growth of germ cells that access the same or the lower part of the brain stem. It is a bad prognosis.


Benign tumors that arise from Schwann cells (whose main function is to produce the myelin that covers axons in the Peripheral Nervous System) are known in this way. They can exist in both cranial and spinal nerves.

What’s a lesion?

Knowing the causes that damage the brain and the consequences that originated in behavior is vital in the study of neuropsychology. Thanks to the appearance of functional and structural neuroimaging techniques, it has been possible to study damaged brain structures from the moment of injury, as well as their subsequent evolution.

Likewise, in most cases, there are physical, cognitive and emotional sequelae that end up generating some type of disability.

Causes of acquired brain damage in adults

In adults, the following causes of acquired brain damage (ABD) stand out.

1. Stroke

Cerebrovascular accidents (CVA) are differentiated into two subtypes: ischemic and hemorrhagic, the former being more frequent. Ischemic strokes are characterized by the interruption of blood flow in a certain area of ​​the brain that prevents the supply of oxygen and glucose, leading to a heart attack. Three main causes are distinguished:

  • Thrombosis. It is the most frequent cause of cerebral infarcts, and its origin is found in the obstruction of an artery due to the formation of a clot or fat pad.
  • Embolism. It is based on the obstruction of an artery as a result of a clot that is dragged from the point where it originated. To read more about this phenomenon you can read this article.
  • Aneurysm. It occurs when an artery is dilated as a result of the weakness of its walls, giving the appearance of an expansive balloon.

On the other hand, hemorrhagic strokes stand out, based on the shedding of blood caused by the rupture of arteries, highlighting intracerebral and subarachnoid hemorrhages.

2. Head injuries

Head injuries are the leading cause of death among the very young. Brain damage is caused as a consequence of external agents such as traffic accidents, falls, work accidents, etc.

Open head injuries are due to brain injuries as a result of injuries to the skull or fractures that reach the brain, although they do not usually affect the state of consciousness.

For its part, closed head injuries are usually accompanied by states of coma, derived mostly from traffic accidents.

In these cases, contusion with small hemorrhages in superficial vessels stands out as the main damage, and axonal damage can also occur with the consequent loss of myelin that may cause deficits in attention, memory and information processing, especially when the lobes involved are frontal and temporal.

3. Tumors

Tumors are expansive processes that can originate in any part of the brain. These are divided into primary, when they originate in the brain itself, or secondary, when they come from metastasis from other areas of the body.

The danger depends on its ability to infiltrate the organ and its ability to proliferate.

The most common are gliomas, derived from glial cells such as astrocytes, being glioblastoma multiforme one of the most lethal, since it tends to rapidly invade brain tissue, so that when it is diagnosed it is usually too late to perform a good treatment.

How do you intervene medically?

Identifying risk factors for brain damage is of vital importance for primary prevention, the main ones being age, genetic vulnerability and previous vascular diseases, as well as the presence of heart disease, hypertension, obesity and substance use, among others.

The prognosis will depend in any case on the age of the patient, as well as the extension and the affected brain area. In the case of stroke, treatment must be very fast, since otherwise it may worsen and series may occur, so in addition to administering drugs that reduce blood pressure, surgical intervention is often necessary to reduce bleeding.

What are the cognitive functions that can be affected after acquired brain damage?

Higher brain functions, such as reasoning, memory or attention are essential to have a full and independent life.

Throughout the day we use our cognitive functions continuously. Our brain uses different cognitive capacities to prepare food, drive or have meetings, activating different parts of the hemispheres to a greater or lesser extent. The basic cognitive functions are as follows:

  • Orientation: the ability that allows us to be aware of ourselves and the context in which we find ourselves at a given moment. Therefore, orientation is assessed using three parameters: personal, spatial and temporal.
  • Attention: state of observation and alertness that allows us to become aware of what is happening in our environment. 

Within this function we must talk about five different processes: selective attention, sustained attention, alternating attention, processing speed and hemineglect.

  • Executive functions are complex mental activities necessary to plan, organize, guide, review and evaluate the behavior necessary to adapt effectively to the environment and to achieve goals. Within the executive functions we find working memory, planning, flexibility, etc.
  • Language: within language, there are different processes that can be affected by acquired brain damage such as vocabulary, expression, comprehension, etc.
  • Memory: ability to effectively encode, store, and retrieve information learned or a lived event. We can distinguish between episodic memory, semantic memory, or procedural memory.

FAQS: Tumor vs lesion

What type of cancer causes lesions?

The most common causes of lesions caused by primary bone cancer are: 

Myeloma multiple. Share on Pinterest Multiple myeloma generally affects people over 50 years of age and is the most common type of primary cancer of the bone.

  • Multiple myeloma. 
  • Osteosarcoma. 
  • Ewing sarcoma. 
  • Chondrosarcoma.

What is considered a lesion?

Damage that develops in the body is an lesion. It is a general term that refers to injuries, falls, blows, burns, arms, and other causes that cause harm.

Do lesions always mean cancer?

No, lesions don’t always mean cancer. 

The word “lesion” is a Latin word for “injury.” It means almost everything that is uncommon in medical parlance. Although it is accurate that the word “lesion” would be used by doctors to describe anything that will later turn out to be cancer.

Does having a tumor mean you have cancer?

An irregular cell growth that serves no function is a tumor. A benign tumor is not a cancer-like malignant tumor. It does not invade surrounding tissue or spread the way cancer does to other parts of the body.

What are the 3 types of lesions?

Types of sports injuries

  • Contusion.
  • Muscle cramp.
  • Contracture
  • Distension.
  • Fibrillar rupture or muscle tear.
  • Complete muscle tear.

In this post we have talked about tumors and lesions, the main types, we had learned the differences between each one and how they are intervened in medicine.

If you have any questions or comments please let us know!


Bilder, R.M. (2011). Neuropsychology 3.0: evidence-based science and practice. J Int Neuropsychol Soc nº 17.

Maas S.; Strocchetti N, Bullock R. (2008). Moderate and severe traumatic brain injury in adults. Lancet Neurol.