Lymphoma - Hodgkin lymphoma- Childhood

Lymphoma - Hodgkin (Childhood)

Overview of the Lymphatic System

The lymphatic system consists of lymph nodes (കഴല), lymphatic organs, and lymphatic vessels. It plays a crucial role in defending the body against infections and diseases. The system circulates lymph, a clear fluid containing lymphocytes (a type of white blood cell). These cells are essential for the immune response and are classified into:

• B cells: Produce antibodies to fight bacteria and infections.

• T cells: Destroy bacteria and fungi, and activate B cells to produce antibodies.

The lymph nodes are small, bean-shaped glands located throughout the body, including the neck, chest, armpits, abdomen, and groin. Other important parts of the lymphatic system include:

• Spleen: Located under the ribs, it produces lymphocytes and filters the blood.

• Thymus: Located behind the breastbone, it plays a role in the development of T cells.

• Tonsils: Located in the throat, they help trap bacteria and viruses.

What is Hodgkin Lymphoma?

Hodgkin lymphoma is a type of cancer that originates in the lymphatic system. It occurs when healthy lymphocytes grow uncontrollably, leading to the formation of tumors. Hodgkin lymphoma most commonly affects the lymph nodes in the neck, chest (mediastinum), under the arms, or in the groin. It can also spread to other organs such as the lungs, liver, bone marrow, and spleen.

Types of Hodgkin Lymphoma

Hodgkin lymphoma is categorized based on the appearance and characteristics of the cancer cells:

1. Classic Hodgkin Lymphoma (cHL)

This type is further divided into:

• Nodular Sclerosis Hodgkin Lymphoma:

• Most common in teens and young adults.

• Typically found in the neck, chest, and abdomen and can spread to the lungs.

• Mixed Cellularity Hodgkin Lymphoma:

• Common in children under 10 years.

• Linked to the Epstein-Barr virus (EBV) and often affects the spleen or abdominal nodes.

• Lymphocyte-rich cHL:

• Rare, occurs in neck, underarm, and groin nodes.

• Can be confused with nodular lymphocyte-predominant Hodgkin lymphoma.

• Lymphocyte-depleted Hodgkin Lymphoma:

• Rare and more aggressive, often affecting bones and bone marrow.

2. Nodular Lymphocyte-predominant Hodgkin Lymphoma

• More common in young males, typically affecting the neck, underarm, or groin nodes.

Statistics

• Children under 14: Hodgkin lymphoma accounts for about 3% of all cancers in this age group.

• Teens aged 15-19: Hodgkin lymphoma represents around 11% of cancers in this group.

Survival Rate

• 5-year survival rate: 99% for children under 14 with Hodgkin lymphoma.

Risk Factors

The exact cause of Hodgkin lymphoma in children is unknown, but the following factors may increase risk:

• Epstein-Barr Virus (EBV): Linked to about 30% of cases.

• Immune system disorders such as:

• Ataxia telangiectasia

• AIDS (Acquired Immune Deficiency Syndrome)

Symptoms

• Painless swelling in the neck, underarm, or groin (lasting several weeks).

• Persistent fever without a clear cause.

• Unexplained weight loss.

• Excessive night sweats.

• Itching.

• Fatigue.

• Shortness of breath or persistent cough.

Diagnosis

1. Physical Examination: Checks for swollen lymph nodes.

2. Blood Tests:

• Complete blood count (CBC)

• Erythrocyte sedimentation rate (ESR)

• Liver and kidney function tests

3. Biopsy:

• Removal and microscopic examination of lymph node tissue to confirm cancer.

• Reed-Sternberg cells (a hallmark of Hodgkin lymphoma) are identified under the microscope.

4. Bone Marrow Biopsy:

• Performed if cancer has spread beyond the lymphatic system.

5. Imaging Tests:

• CT Scan, PET-CT, MRI: Help determine the extent of the cancer.

Treatment Options

1. Chemotherapy

• Uses drugs to kill cancer cells.

• Common chemotherapy regimens include:

• ABVD: Doxorubicin, bleomycin, vinblastine, and dacarbazine.

• MOPP: Mechlorethamine, prednisone, procarbazine, and vincristine.

• Newer regimens replace mechlorethamine with cyclophosphamide and procarbazine with etoposide to reduce infertility risks.

2. Targeted Therapy

• Targets specific proteins or genes in cancer cells.

• Common drugs:

• Brentuximab vedotin (Adcetris)

• Rituximab (Rituxan)

3. Immunotherapy

• Boosts the immune system to fight cancer cells.

• Common drugs:

• Nivolumab (Opdivo)

• Pembrolizumab (Keytruda)

4. Radiation Therapy

• Uses high-energy beams to destroy cancer cells.

• Radiation is now targeted only to areas where chemotherapy was not fully effective.

• Side Effects: Fatigue, itching, throat pain, digestive discomfort, and long-term risks such as growth delays and damage to bones, heart, or thyroid.

5. Stem Cell Transplantation

• Used after high-dose chemotherapy or radiation to restore healthy bone marrow.

• Autologous transplant (AUTO): Uses the patient’s own stem cells.

• Allogeneic transplant (ALLO): Uses stem cells from a donor.

Follow-up Care

Regular follow-up visits are essential after treatment to monitor for cancer recurrence and manage side effects. Follow-up care includes:

• Physical exams

• Blood tests

• Imaging tests (as needed)

Hodgkin lymphoma in childhood is highly treatable, especially when diagnosed early, with a very high survival rate. Advances in treatment and targeted therapies continue to improve outcomes and reduce long-term side effects.

‍