Pediatric Diffuse Intrinsic Pontine Glioma

Introduction

Pediatric diffuse intrinsic pontine glioma is a malignancy of the brainstem. It is highly aggressive and invasive. It is a high-grade tumor with rapid progression, which is not easy to treat. It occurs in the lowest stem-like part of the brainstem, the pons. Pons control the vital functions of the human body such as respiratory rate, heart rate, balance, sleeping, bladder control, and blood pressure. As the tumor grows, it starts putting pressure on another part of the brain affecting the nervous and muscular systems. It is one of the most common tumors of the central nervous system found in childhood. The tumor is highly infiltrative and associated with a high morbidity rate. It can be found at any age but is more commonly found in the age range of nine to fifteen.

What Is the Cause of Pediatric Diffuse Intrinsic Pontine Glioma?

Pediatric diffuse pontine intrinsic glioma is known as glioma as it grows from glial cells. Glial cells are a type of supportive cell in the brain. During cell division, cells of the spinal cord and brain cells grow and divide. In this process of cell division, replication of genetic material takes place. During this phase, if the mutation occurs, ependymal cells grow into a tumor. There is no association of environmental factors, and there is no inheritance from parents to offspring.

What Are the Stages of Pediatric Diffuse Intrinsic Pontine Glioma?

Pediatric diffuse pontine intrinsic glioma is classified in the staging system. Stages are based on types of cells seen microscopically. However, pediatric diffuse intrinsic pontine glioma is not classified in grading because the tumor is confirmed after biopsy. Most of the time, pediatric diffuse intrinsic pontine glioma is diagnosed in grade three and grade four. The grades of the tumor vary from severe to most severe.

Following is the order.

• Low Grade.

  • Pilocytic stage.

  • Fibrillary stage.

• High Grade.

  • Anaplastic stage.

  • Glioblastoma multiforme.

What Are the Symptoms of Pediatric Diffuse Intrinsic Pontine Glioma?

As the tumors grow rapidly, signs and symptoms are seen in children progressively. The symptoms develop before diagnosis as the tumor is aggressive.

Following are the signs and symptoms seen.

1. Difficulty in walking.

2. Difficulty in balance.

3. Double vision.

4. Drooping eyelids.

5. Uncontrolled eye movements.

6. Blurred vision.

7. Difficulty in chewing.

8. Difficulty in mastication.

9. Nausea and vomiting.

10. Headache during the morning.

11. Muscular weakness.

12. Weakness in arms and legs.

13. Difficulty in walking and coordination.

14. Slurred speech.

15. Drooping of face.

How Is Pediatric Diffuse Intrinsic Pontine Glioma Diagnosed?

Pediatric diffuse pontine intrinsic glioma is diagnosed by advanced medical imaging studies. Recent advancement in neurosurgical techniques helps in avoiding biopsy. The pediatrician reviews the diagnostic test results and recommends the best treatment available to the child. The pediatrician performs a medical and complete physical examination.

Other than that, the following tests are performed.

1. Computerized tomography scan.

2. Magnetic resonance imaging.

3. Magnetic resonance spectroscopy.

4. Biopsy.

What Is the Treatment Plan for Pediatric Diffuse Intrinsic Pontine Glioma?

Pediatric diffuse intrinsic pontine glioma is an aggressive tumor. It infiltrates aggressively as a high-grade tumor; therefore, treatment should be started immediately as soon as possible. The goal of treatment is to stabilize neurological symptoms in the child.

Following is the treatment plan.

• Steroid: Dexamethasone is given as a steroid to a child. It helps in stabilizing the blood-brain barrier system. It helps in improving tissue penetration in chemotherapy and radiotherapy.

• Radiation Therapy: Radiation therapy is the first line treatment plan followed after the diagnosis. In radiation therapy, high-energy radiation waves are used to destroy the tumor cells. The period of radiation therapy is six to nine months. Conventional limited field radiotherapy and hypofractionated radiotherapy are used. However, radiation therapy produces a transient response.

• Chemotherapy: It is used as an adjunct to radiotherapy. It increases the survival rate of the child. Doctors choose drugs to be administered after the biopsy. Temozolomide, Gemcitabine, Capecitabine, and tyrosine kinase inhibitors (TKI) are used.

• Multimodal Immunotherapy: It consists of vaccination cycles and immunogenic cell death therapy. Temozolomide local modulated electro hyperthermia is used to improve the overall survival rate.

• Palliative Therapy: Palliative therapy consists of palliative care given to a child. It is indicated for relief of pain and symptoms caused by the tumor. Palliative therapy is done along with radiation therapy and chemotherapy.

• Surgery: Surgery is rarely performed because of the tumor's location in the brain. Surgery can be performed to obtain a specimen for biopsy, but removing the whole tumor with surgery is rarely done.

What Are the Surgical Complications of Pediatric Diffuse Intrinsic Pontine Glioma?

Following are the complications of pediatric diffuse intrinsic glioma.

• Dysphagia.

• Hemiparesis.

• Facial paralysis.

• Deep vein thrombosis.

• Herniation in the brain.

• Respiratory insufficiency.

• Coma.

• Edema.

• Seizures.

• Intracranial hemorrhage.

• Nerve injury.

What Is the Prognosis of Pediatric Diffuse Intrinsic Pontine Glioma?

The survival rate of Pediatric diffuse intrinsic pontine glioma is less because of the absence of effective treatment. The median survival range is in between eight to eleven months. However, it has increased due to recent advancements in research and early diagnosis of tumors. The survival rate increases if the patient is younger than ten years of age, has fewer symptoms, and if the extension of the tumor is not beyond the pons.

What Should Parents Do?

Parents' support, love, and strength are needed for a child's survival. There are certain instructions parents should follow.

1. Always be honest with the child.

2. Always include the child in the conversation.

3. Parents should allow their children to express grief.

4. Parents should take care of their children's physical comfort and quality of life.

Conclusion

Pediatric diffuse intrinsic pontine glioma is a malignancy of the brain which is highly invasive. It spreads to other brain parts rapidly; therefore, early diagnosis is important for survival. Various therapies have been tested to treat this tumor. Parents should take care of and support their children as much as possible, no matter the survival rate and timeline.