Definition: Abnormal masses of tissue that result when cells divide more than they should or do not die when they should. These growths can be benign (not cancerous) or malignant (cancerous).

Benign Tumors: These are non-cancerous growths. They do not spread to other parts of the body and are generally not life-threatening, though they can cause problems if they press on nearby organs or tissues.

Malignant Tumors (Cancers): These are cancerous growths. They have the ability to invade nearby tissues and spread to other parts of the body (metastasize). Early diagnosis and treatment are crucial.

Common Types of Tumors in Children:

• Leukemias: Cancers of the blood and bone marrow. Acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are the most common.
• Brain and Spinal Cord Tumors: The most common solid tumors in children. Examples include gliomas, medulloblastomas, and ependymomas.
• Neuroblastoma: A cancer that develops from immature nerve cells (neuroblasts) in several areas of the body, most commonly in and around the adrenal glands.
• Wilms Tumor (Nephroblastoma): A type of kidney cancer that most often affects young children.
• Lymphomas: Cancers that begin in cells of the immune system. Hodgkin lymphoma and non-Hodgkin lymphoma are the two main types.
• Rhabdomyosarcoma: A type of sarcoma (cancer of connective tissues) that arises from cells that normally develop into skeletal muscles.
• Retinoblastoma: A cancer of the eye that begins in the retina.
• Bone Cancers: Osteosarcoma (typically develops in growing bones around the knee) and Ewing sarcoma (can occur in any bone but often in the pelvis, thigh bone, or ribs) are the most common primary bone cancers in children.
• Germ Cell Tumors: Tumors that begin in the cells that give rise to sperm or eggs. They can occur in the ovaries or testes, or less commonly in other parts of the body like the chest, abdomen, or brain.

General Signs and Symptoms (can vary greatly depending on tumor type and location):

• An unusual lump or swelling
• Unexplained paleness and loss of energy
• Easy bruising or bleeding
• Ongoing pain in one area of the body
• Limping
• Unexplained fever or illness that doesn’t go away
• Frequent headaches, often with vomiting
• Sudden eye or vision changes
• Rapid weight loss

Diagnostic Approaches:

• Medical History and Physical Examination: Gathering information about symptoms, family history, and conducting a physical check.
• Blood Tests: To check blood cell counts, organ function, and look for tumor markers.
• Imaging Studies:
  
  • X-rays: To look for tumors in bones or the chest.
  • Ultrasound: Uses sound waves to create images of organs and soft tissues.
  • Computed Tomography (CT) Scan: Provides detailed cross-sectional images of the body.
  • Magnetic Resonance Imaging (MRI): Uses strong magnets and radio waves to create detailed images, particularly useful for brain and spinal cord tumors.
  • Positron Emission Tomography (PET) Scan: Can help determine if a tumor is cancerous and if it has spread by looking at metabolic activity.
• Biopsy: Removal of a small sample of tissue from the tumor for examination under a microscope by a pathologist. This is often the definitive way to diagnose cancer and determine its specific type.
  
  • Needle biopsy: A thin needle is used to remove tissue or fluid.
  • Surgical biopsy: Part or all of the tumor is removed surgically.
• Bone Marrow Aspiration and Biopsy: Often done if leukemia or lymphoma is suspected, or to see if cancer has spread to the bone marrow.

Treatment Modalities:

Treatment depends on the type of tumor, its location, its stage (how much it has spread), and the child’s overall health. Often, a combination of therapies is used.

• Surgery: Aims to remove the tumor. It can be the primary treatment for many solid tumors.
• Chemotherapy: Uses powerful drugs to kill cancer cells. These drugs can be given orally, intravenously, or intrathecally (into the spinal fluid).
• Radiation Therapy: Uses high-energy rays (like X-rays) or particles to kill cancer cells or shrink tumors.
• Immunotherapy: A type of treatment that helps the body’s own immune system fight cancer.
• Targeted Therapy: Uses drugs or other substances that attack specific cancer cells with less harm to normal cells.
• Stem Cell Transplant (also known as Bone Marrow Transplant): Allows for high doses of chemotherapy (and sometimes radiation) to be given. After these treatments, healthy stem cells are infused to restore the bone marrow.
• Supportive Care: Manages side effects of cancer and its treatment, including pain management, nutritional support, and psychological support.