Brain Tumors: Types, Symptoms, Diagnosis, and Treatment Methods

Brain Tumors: Types, Symptoms, Diagnosis, and Treatment Methods

Brain Tumors, their Types, Symptoms, Diagnosis, and Treatment Methods are covered in this content we have prepared, including Superficial Metastatic Brain Tumors, Deep Metastatic Brain Tumors, Skull Base Tumors, Posterior Fossa Tumor Surgery, Cerebellopontine Angle Tumor Surgery, Skull Bone/Scalp Simple Tumor Masses, Third Ventricular Tumors, Fourth Ventricular Tumors, Convexity Tumor Surgery, and Cervical Intramedullary Tumor Excision.

Superficial Metastatic Brain Tumors

Metastatic brain tumors are those that form when the tumor spreads to the brain from another part of the body. In superficial metastatic brain tumors, the location of the brain tumor is on the outer surface of the brain. Metastatic brain tumors are among the most commonly encountered types of brain tumors. According to autopsy studies, metastatic brain tumors, which are more prevalent than all other brain tumor types combined, are found in 20-50% of cancer patients.

The cancer types most frequently causing metastatic brain tumors are breast cancer in women and lung cancer in men. Metastatic brain tumors generally develop as a result of cancer cells from another location reaching the brain through the bloodstream. Cancer cells that enter the bloodstream progress to the brain and cause the formation of new cancer cells in that region. For this reason, metastatic brain tumors most commonly arise in areas of the brain with greater blood circulation.

Metastatic brain tumors most often develop in multiple numbers. Accordingly, the treatment approach for metastatic brain tumors is planned based on the number, size, and location of the metastases. Since metastatic brain tumors fundamentally consist of abnormally growing and multiplying cancer cells, the space they occupy in the brain causes increased intracranial pressure.

For this reason, the symptoms of metastatic brain tumors are similar to those of increased intracranial pressure. These symptoms can be listed as nausea, vomiting, vision disorders, weakness in different parts of the body depending on the affected brain region, tingling, sensory loss, and in some cases seizures. Especially when such symptoms appear in a patient with cancer, a doctor should be consulted promptly and necessary examinations should be performed.

After metastatic brain tumors are detected, depending on the patient's condition, chemotherapy, radiotherapy, surgery, or combinations of these treatment methods may be used during the treatment process. If metastatic brain tumors are not treated in a timely manner, they may pose serious health risks. The most commonly used treatment method is radiotherapy.

In radiotherapy, the growth and multiplication of tumor cells are stopped through radiation, and these cells are targeted to reduce tumor size. The effectiveness of radiotherapy varies depending on the type of cancer cell. Some cancer cells respond noticeably to the applied radiation and can be controlled more readily, while some cancer cell types are not sufficiently affected by radiotherapy. In such cases, surgical options may need to be applied in addition to radiotherapy.

Metastatic brain tumor surgery is most commonly applied in non-diffuse tumors located in a specific region, large tumors that cause neurological symptoms. Because metastatic brain tumors are superficial, pre-operative tumor detection and easier tumor access during surgery may help reduce damage to brain tissue, potentially lowering the side effects and risks of surgery.

Following metastatic brain tumor surgery, radiotherapy or chemotherapy may be applied to support treatment. Although chemotherapy in metastatic brain tumors is generally considered less effective than surgery or radiotherapy, it may contribute to extending survival time in some types of cancer cells, depending on the individual case.

Deep Metastatic Brain Tumors

Deep metastatic brain tumors are located in the deep tissue of the brain. In metastatic brain tumors seen in the deep tissues of the brain, depending on the tumor's location, the patient's complex functions such as emotional regulation, memory, and learning functions may be affected. The fact that metastatic brain tumor is located deep may increase the side effects and risks of surgery since tumor detection before surgery and access to the tumor during surgery are more difficult.

Skull Base Tumors

The skull base is a complex bony anatomical structure formed by the frontal, ethmoid, sphenoid, temporal, and occipital bones, serving as a barrier between the brain and neck tissues. Since the clinical evaluation of skull base tumors is limited, computed tomography (CT) and magnetic resonance (MR) imaging methods play an important role in the diagnosis and treatment process of these patients.

Particularly in recent years, with advances in imaging methods, precise pre-operative determination of tumor boundaries and the establishment of tumors' relationships with vital neural and vascular structures have become possible, enabling surgeons to develop approaches aimed at minimizing vital risks while addressing tumor clearance as much as feasible.

Accurate evaluation of the positions, extensions, and relationships with important surrounding structures of tumors located at the skull base, as well as determination of tumor characteristics, requires detailed knowledge of skull base anatomy. The skull base is composed of different bones named frontal, ethmoid, sphenoid, temporal, and occipital.

The skull base, with many different foramina and grooves created and possessed by these bones, is a highly complex anatomical structure serving as a barrier between intracranial tissues and extracranial soft tissues. Additionally, it is an important structure protecting vital structures within the skull from external factors. The skull base can present both benign and malignant bone tumors and metastases. Metastatic tumors are among the most common tumor types seen at the skull base in adult patients.

Since metastatic tumors frequently spread hematogenously, they most commonly arise in skull base structures with dense bone marrow, such as the clivus, petrous apex, sphenoid triangle, and diploic cavities in the calvarium. Besides these, the most common malignant tumor seen at the skull base is osteosarcoma, generally occurring in individuals who previously received radiotherapy and patients with Paget's disease.

Osteosarcomas are characterized by bone formation and aggressive periosteal reaction accompanying this formation process. Apart from these, skull base tumors can present in many different locations and forms. Depending on their location of origin, tumor type, extension, and size, they can cause different symptoms and, in advanced cases, may pose serious health risks and cause permanent damage to the patient.

Depending on the tumor's location, anatomical structures such as the frontal fossa, temporal fossa, sphenoid bone, and clivus may be affected. Of these, frontal fossa tumors are tumor types affecting the anterior portion of the skull base. Temporal fossa tumors are those arising on the lateral sides of the skull base. The sphenoid bone, another region where skull base tumors can appear, is both located in the middle part of the skull base and contributes to the formation of the anterior part of the temples.

Another structure, the clivus, forms part of the skull base, is responsible for protecting the brain and separating it from other structures around the face and neck. Skull base tumors can thus arise in many different locations. Depending on their location, they can cause different effects on both the brain and surrounding tissues. In this context, skull base tumors can manifest themselves with many different symptoms in the patient in which they develop, and in some cases, if not monitored and managed, they may pose serious health risks.

Posterior Fossa Tumor Surgery

The posterior fossa is the anatomical structure corresponding to the posterior one-third of the skull. The locations where brain tumors develop can vary with age. Posterior fossa tumors can be located in two regions: supratentorial and infratentorial. In adult patients, approximately 70-75% of brain tumors are located in the supratentorial region, named as the area between the cerebellum and brain but closer to the brain.

In childhood, the ratio of tumors located in the infratentorial region, named as the area between the cerebellum and brain but closer to the brain, is at the level of 60-70%. The symptoms and signs of posterior fossa tumors initially develop due to increased intracranial pressure, and secondarily due to compression on neurological structures called cerebellar nuclei and brainstem.

Additionally, cerebrospinal fluid (CSF) circulating throughout our body along our brain and spinal cord may create a blockage in its circulation pathways, causing a health problem called hydrocephalus where cerebrospinal fluid accumulates, increasing intracranial pressure, and the patient may seek medical attention with symptoms and signs related to hydrocephalus.

Patients with posterior fossa tumors may present different findings depending on the tumor's location, type, size, and patient's general condition. However, in general, patients seek medical attention with findings such as headache, nausea, vomiting, dizziness, balance disturbance, ataxia (coordination disorder in movements), diplopia (a type of vision disorder causing double vision), weakness, and vision disturbance. Due to the structure of the posterior fossa, the time between the appearance of patient complaints and posterior fossa tumor diagnosis is often shorter compared to other brain tumors.

Depending on tumor severity, this period can be even shorter, decreasing to one week. However, in some benign tumors, this period can extend up to one year. After posterior fossa tumor diagnosis is confirmed, the treatment method to be used is determined by the treating physician. When surgical treatment is decided, before posterior fossa tumor surgery, the tumor must be evaluated in particular detail, surrounding tissues must be well understood, and support from advanced imaging methods should be obtained during surgical procedure planning.

After the surgical procedure is determined by the surgeon, posterior fossa tumor surgery is most commonly performed in a sitting position with the aid of a pin headrest. However, this may vary depending on the patient's general condition and the surgeon's opinion. Depending on the tumor's location, access can be made from different regions to remove the tumor. Similarly, depending on the tumor's location and structure, all or part of it can be removed.

In cases where the tumor is malignant or cannot be completely removed, in addition to surgical treatment, chemotherapy and radiotherapy methods are also employed. The treatment of posterior fossa tumors has seen developments in recent years through advances in diagnosis and treatment methods, surgical techniques and technology, and supportive treatments such as chemotherapy and radiotherapy; outcomes for patients undergoing treatment can vary by individual case, and prognosis should be discussed with the treating physician.

Cerebellopontine Angle Tumor Surgery

In medical terminology, the junction of the cerebellum and brainstem is defined as the cerebellopontine angle. Many different types of tumors can develop in this region. However, the most commonly encountered tumor type in this region is tumors arising in the sheath of the eighth cranial nerve, the vestibular nerve responsible for balance and hearing. These types of tumors are generally benign and slow-growing.

Cerebellopontine angle tumors most commonly compress the vestibular nerve, causing hearing and balance problems. If the cerebellopontine angle tumor becomes very large, it may extend to the face and compress the nerve responsible for facial sensation. In such cases, numbness may occur in the face. More enlarged tumors can cause compression damaging these nerves, and manifestations can reach facial paralysis.

Similarly, an excessively enlarged cerebellopontine angle tumor can compress the brainstem, which may pose a serious health risk for the patient and cause permanent damage. Cerebellopontine angle tumors are most commonly unilateral. However, in the presence of a disease called neurofibromatosis type 2, cerebellopontine angle tumors can be bilateral.

Cerebellopontine angle tumors account for approximately 8% of all brain tumors. Early diagnosis is considered important for monitoring tumor growth and reducing the likelihood of permanent damage or serious complications. In most cerebellopontine angle tumor patients, hearing loss is the initial symptom. Due to vestibular nerve involvement, symptoms such as dizziness, headache, and tinnitus may also develop. In cerebellopontine angle tumors reaching severe sizes, facial paralysis, double vision, swallowing disorders, facial pain, and numbness may be seen.

For this reason, seeking medical attention while symptoms are still in early stages may support earlier disease management. When planning surgical treatment of cerebellopontine angle tumors, the surgical procedure is determined based on the tumor's type, its relationship with other nerves, and the condition of surrounding tissues. Small-size tumors detected through early diagnosis are generally considered more manageable surgically, and the likelihood of unwanted side effects such as hearing loss after surgery may be lower, though outcomes vary by case.

However, surgery is more difficult in large tumors, and due to the intense compression caused by the tumor, nerves and surrounding tissues in the region may have sustained permanent damage. In such cases, even if the tumor is completely removed surgically, the damage left by the tumor may be permanent. Surgical treatment outcomes for cerebellopontine angle tumors vary by individual case, and information about tumor recurrence risk