Primary Brain Lymphoma: Symptoms, Diagnosis and Treatment

Primary brain lymphoma, also called primary central nervous system lymphoma or PCNSL, is a rare type of non-Hodgkin lymphoma that begins within the central nervous system. It may affect the brain, meninges, spinal cord, cerebrospinal fluid, and, in some patients, the eyes.

Unlike cancers that begin elsewhere and later spread to the brain, PCNSL originates in the central nervous system and does not show evidence of disease outside this area at the time of diagnosis. Most cases are a type known as diffuse large B-cell lymphoma.

Its symptoms can resemble those of other neurological disorders. For this reason, an MRI alone is not usually enough to establish the diagnosis. A tissue sample obtained through a brain biopsy is commonly required, followed by a multidisciplinary evaluation.

At BlueNetHospitals Los Cabos, our Neurosurgery specialists participate in evaluating brain lesions and planning diagnostic procedures in coordination with Neurology, Hematology, Oncology, Radiology, and other specialties.

Primary central nervous system lymphoma is a cancer of lymphocytes, the immune cells that normally help protect the body from infections.

In PCNSL, some lymphocytes become malignant and accumulate inside the central nervous system. Lesions may develop in one or several areas and involve:

• The brain.
• The meninges surrounding the brain and spinal cord.
• The cerebrospinal fluid.
• The spinal cord.
• The retina or vitreous of the eyes.

Although the term “primary brain lymphoma” is widely used, primary central nervous system lymphoma is more accurate because the condition is not always limited to brain tissue.

No. A brain metastasis develops when cancer originating in another part of the body spreads to the brain.

PCNSL begins within the central nervous system. It must also be distinguished from systemic lymphoma with secondary brain or meningeal involvement because the evaluation and treatment may differ.

After confirming the diagnosis, the medical team performs additional tests to make sure lymphoma is not present elsewhere in the body.

The exact cause is unknown. In many patients, no specific trigger can be identified.

The risk is higher in people with significant immune system impairment, including those with:

• Poorly controlled HIV infection.
• A history of organ transplantation.
• Long-term use of certain immunosuppressive medications.
• Some congenital immunodeficiencies.
• Certain conditions that affect immune function.

In immunocompromised patients, the Epstein-Barr virus may contribute to the development of the disease.

However, many cases now occur in people without a known immunodeficiency. Older age is associated with a higher incidence, although PCNSL can also develop in younger adults.

Having one of these risk factors does not mean that a person will develop PCNSL, and having no recognized risk factors does not rule it out.

Symptoms depend on the location of the lesions and how quickly they develop. They may progress over days or weeks, although the course varies.

Possible symptoms include:

• Memory or concentration problems.
• Confusion.
• Personality or behavioral changes.
• Weakness in an arm, leg, or one side of the body.
• Difficulty speaking or understanding language.
• Balance or coordination problems.
• Difficulty walking.
• Persistent headaches.
• Nausea or vomiting.
• Seizures.
• Unusual drowsiness.
• Visual disturbances.
• Loss of sensation.
• Changes in consciousness.

Unlike many systemic lymphomas, general symptoms such as fever, drenching night sweats, and unexplained weight loss are not always present because the disease is often limited to the central nervous system.

Primary central nervous system lymphoma may also affect the eyes. This is known as vitreoretinal lymphoma and may cause:

• Blurred vision.
• Floaters or spots in the visual field.
• Reduced vision.
• Sensitivity to light.
• Persistent visual changes in one or both eyes.

Eye involvement may appear together with brain lesions or, in some cases, be the first sign of the disease. A specialized ophthalmological examination may therefore be part of the evaluation.

Certain neurological symptoms require immediate medical assessment, regardless of their cause.

Go to the emergency department if someone experiences:

• A first seizure.
• Sudden weakness in the face, arm, or leg.
• Sudden difficulty speaking.
• Sudden loss of vision.
• Severe confusion.
• Loss or deterioration of consciousness.
• A severe headache accompanied by vomiting.
• A seizure lasting five minutes or longer.
• Repeated seizures without full recovery.
• Difficulty breathing after a seizure.

These symptoms may also indicate a stroke or another neurological emergency. Do not wait for them to disappear on their own.

🚑 BlueNetHospitals Ambulance Service: +52 (624) 104 3911

Diagnosis requires a combination of symptoms, neurological examination, imaging, and tissue analysis.

The process may involve Neurosurgery, Neurology, Hematology, Oncology, Neuroradiology, Ophthalmology, and Pathology.

The specialist may evaluate:

• Strength and sensation.
• Reflexes.
• Speech and language.
• Memory and attention.
• Coordination.
• Balance.
• Walking.
• Cranial nerve function.
• Mental status and level of consciousness.

The medical team will also review the patient’s health history, medications, immune conditions, and progression of symptoms.

A contrast-enhanced MRI is usually the main imaging test. It helps identify the number, size, and location of lesions, as well as surrounding swelling and pressure on nearby structures.

PCNSL may have features that suggest the diagnosis, but imaging alone cannot confirm it. Gliomas, metastases, infections, inflammatory disorders, and other conditions can have a similar appearance.

A CT scan may be used in emergencies or when MRI is unavailable or contraindicated. It can identify lesions, bleeding, hydrocephalus, and displacement of brain structures, although it provides less soft-tissue detail than MRI.

A stereotactic brain biopsy is usually the main diagnostic procedure. Using imaging guidance, the neurosurgeon obtains a small tissue sample through a carefully planned pathway.

The tissue is analyzed to determine:

• The type of lymphoma.
• The characteristics of the malignant cells.
• Immunological and molecular markers.
• Whether another condition may be mimicking lymphoma.

A biopsy allows the medical team to select the appropriate treatment. In PCNSL, surgery usually serves a diagnostic purpose. Removing the entire visible lesion is not the standard initial approach because the disease may be multifocal and can infiltrate tissue beyond what is visible on imaging.

A more extensive resection may be considered in carefully selected situations, but it is not the standard strategy for every patient.

Corticosteroids such as dexamethasone can quickly reduce swelling and improve neurological symptoms. However, PCNSL is particularly sensitive to these medicines.

When corticosteroids are given before a biopsy, the lesion may temporarily shrink or change, making it harder to obtain a conclusive tissue diagnosis.

If PCNSL is suspected and the patient is medically stable, the team may avoid or delay corticosteroids until after the tissue sample has been obtained.

This does not mean that corticosteroids should never be used. If there is significant brain swelling, rapid neurological deterioration, or an immediate threat to the patient, the medical team may decide that urgent treatment is more important.

Never begin, stop, or change corticosteroid therapy without medical instructions.

Some patients undergo a lumbar puncture to look for malignant cells, proteins, genetic material, or other markers in the cerebrospinal fluid.

Lumbar puncture is not appropriate for everyone. Imaging must first rule out increased intracranial pressure, a mass with significant pressure effects, or another contraindication.

A negative cerebrospinal fluid test does not rule out PCNSL.

Because PCNSL may involve the retina and vitreous, the medical team may request an evaluation by an ophthalmologist experienced in inflammatory or oncological eye conditions.

The examination may include:

• Slit-lamp evaluation.
• Examination of the retina and optic structures.
• Optical coherence tomography.
• Vitreous or retinal testing in selected cases.

After diagnosis, the medical team checks whether lymphoma is present in another part of the body. This helps distinguish PCNSL from systemic lymphoma with secondary central nervous system involvement.

Testing may include:

• A complete physical examination.
• Blood tests.
• HIV testing.
• CT or PET-CT imaging.
• Bone marrow evaluation in selected cases.
• Testicular ultrasound in certain patients.
• Additional studies based on symptoms and medical history.

The diagnostic plan is tailored to each patient.

Treatment depends on age, overall health, kidney function, the extent of the disease, eye involvement, and the patient’s ability to tolerate intensive therapy.

Because PCNSL is complex, treatment should be planned by a multidisciplinary team experienced in central nervous system lymphomas.

High-dose methotrexate is the foundation of most initial treatment regimens because it can reach therapeutic concentrations within the central nervous system.

It is usually combined with other medicines. Depending on the protocol and the patient, these may include:

• Rituximab.
• Cytarabine.
• Procarbazine.
• Temozolomide.
• Thiotepa.
• Other agents selected by Hematology and Oncology.

High-dose methotrexate requires specialized monitoring, hydration, rescue medication, kidney function assessment, and measurement of drug levels.

The regimen is not the same for every patient. It must be adjusted according to age, kidney function, functional status, and other medical conditions.

After the disease responds to initial therapy, consolidation may be recommended to prolong that response.

Options may include:

• Additional chemotherapy.
• High-dose chemotherapy followed by autologous stem cell transplantation.
• Whole-brain radiation therapy in selected situations and at carefully chosen doses.
• Less intensive strategies for patients who cannot tolerate aggressive treatment.

The choice depends on the initial response, age, functional status, and potential treatment side effects.

Whole-brain radiation can control PCNSL, but it is not usually used alone as the first treatment in patients who can receive chemotherapy. Relapse is common after radiation alone, and there is a risk of delayed neurological toxicity.

This risk is particularly important in older adults and may affect:

• Memory.
• Attention.
• Thinking speed.
• Balance.
• Independence.

Radiation therapy continues to have a role in selected patients, as consolidation or in certain cases of recurrent disease. Its timing and dose must be individualized.

Corticosteroids may reduce brain swelling and quickly relieve some symptoms, but they do not replace cancer-directed treatment.

Their use must be carefully coordinated with the biopsy because they can alter the lesion and complicate diagnosis.

When vitreoretinal lymphoma is present, treatment may include systemic therapy, medication delivered directly into the eye, or ocular radiation in selected cases.

Management requires coordination among Ophthalmology, Hematology, and Oncology.

PCNSL may return after an initial response. Treatment of recurrent disease depends on:

• How long the previous response lasted.
• Which medicines were previously used.
• Age and functional status.
• Location of the recurrence.
• Kidney and organ function.
• Whether the patient is eligible for autologous stem cell transplantation.

Options may include high-dose methotrexate again in selected patients, other chemotherapy regimens, targeted therapies, immunotherapy, radiation, autologous transplantation, or participation in clinical trials.

Neurosurgery plays a central role in safely obtaining tissue to confirm the diagnosis.

The neurosurgeon:

• Reviews the MRI and location of the lesions.
• Plans the safest pathway for tissue sampling.
• Assesses the risk of bleeding or neurological injury.
• Performs the stereotactic biopsy or other indicated procedure.
• Treats complications such as hydrocephalus or increased intracranial pressure in selected cases.
• Participates in multidisciplinary treatment planning.

Unlike many other brain tumors, PCNSL is not generally treated by removing the entire lesion. After the diagnosis is confirmed, the main treatment is usually medical and directed by Hematology, Oncology, and Neuro-oncology.

The outlook varies significantly from one patient to another and depends on factors such as:

• Age.
• Functional status.
• Location and extent of disease.
• Kidney function.
• Cerebrospinal fluid or eye involvement.
• Immune system function.
• Response to treatment.
• Ability to complete treatment and consolidation.

PCNSL may respond substantially to treatment, but it also has a risk of recurrence. Patients need regular clinical evaluations and follow-up imaging during and after therapy.

General survival statistics cannot predict what will happen in an individual case. The treating team can provide more useful guidance after reviewing the pathology, extent of disease, and initial response.

The condition may affect mobility, memory, behavior, independence, and emotional well-being. Treatment can also cause fatigue, nausea, infection risk, or cognitive changes.

Comprehensive care may include:

• Physical rehabilitation.
• Occupational therapy.
• Speech and language therapy.
• Neuropsychological evaluation.
• Nutritional support.
• Seizure management.
• Psychological support.
• Guidance for relatives and caregivers.
• Palliative care to control symptoms at any stage.

Palliative care does not mean stopping cancer treatment. It can be provided alongside active therapy to manage symptoms and support quality of life.

Follow-up care may include:

• Regular medical appointments.
• Neurological examinations.
• Follow-up brain MRI scans.
• Eye evaluations when ocular involvement is present.
• Blood tests.
• Monitoring of kidney and organ function.
• Assessment of memory, balance, and independence.
• Surveillance for delayed treatment effects.

Tell your medical team if memory problems, personality changes, weakness, visual symptoms, seizures, or difficulty walking return or worsen.

Request medical evaluation if you experience persistent or progressive neurological symptoms such as:

• Memory or personality changes.
• Difficulty speaking.
• Weakness on one side of the body.
• Balance problems.
• Persistent visual disturbances.
• Seizures.
• Headaches accompanied by vomiting or neurological changes.
• Worsening confusion.

These symptoms do not necessarily mean that a person has PCNSL. Many conditions can cause similar problems, but proper evaluation is necessary to determine the cause.

If imaging has identified a brain lesion or you are experiencing progressive neurological symptoms, a specialist evaluation can help define the next steps.

At BlueNetHospitals Los Cabos, our Neurosurgery specialists evaluate central nervous system lesions and coordinate the studies or procedures needed to reach an accurate diagnosis.

📲 Schedule an appointment with our Neurosurgery specialist via WhatsApp: +52 (624) 151 0693

This article provides general educational information and does not replace a personalized medical evaluation.

It is a rare type of non-Hodgkin lymphoma that begins within the central nervous system. It may affect the brain, meninges, cerebrospinal fluid, spinal cord, and eyes.

It is a tumor of the central nervous system, but it develops from lymphocytes rather than the nerve or glial cells that give rise to many other brain tumors.

Possible symptoms include memory problems, personality changes, weakness, speech or vision difficulties, balance problems, headaches, seizures, and confusion.

An MRI can suggest the diagnosis, but a brain biopsy is usually required to analyze the tissue. Cerebrospinal fluid, eye, blood, and body imaging studies may also be performed.

PCNSL may temporarily shrink after corticosteroids are given, making it difficult to obtain a diagnostic tissue sample. If the patient is stable, the team may delay corticosteroids until after the biopsy.

Surgery is usually used to obtain a biopsy rather than to remove the entire lesion. The main treatment is generally based on chemotherapy, although some situations may require additional neurosurgical procedures.

The foundation of treatment is usually high-dose methotrexate chemotherapy combined with other medicines. Consolidation may involve additional chemotherapy, autologous stem cell transplantation, or radiation in selected patients.

No. Radiation may be useful, but it is selected carefully because of the risk of delayed neurological effects, particularly in older adults.

Yes. PCNSL has a risk of recurrence even after a good initial response. Regular appointments and follow-up MRI scans are therefore essential.

Seek immediate care for a first seizure, sudden weakness, sudden difficulty speaking, loss of consciousness, rapidly worsening neurological symptoms, or a severe headache accompanied by vomiting.