Rare Pediatric Oncological Conditions: An Overview

Introduction:

Pediatric oncology is the study of the diagnosis and management of cancer in individuals below the age of 18 or 20. It focuses on the treatment of cancer in children and young adults. While some cancers in children, such as leukemia (a type of blood cancer) and brain tumors, are well-known, some rare oncological conditions often go unnoticed due to their rarity. These conditions provide unique challenges in terms of diagnosis and treatment options. This article briefly discusses the rare oncological conditions seen in children.

What Are Rare Pediatric Oncological Conditions?

Rare pediatric oncological conditions are uncommon cancers that affect children. Due to their rarity, healthcare professionals may face challenges in diagnosing and providing effective treatment strategies. Rare pediatric oncological conditions include:

1. Head and Neck Cancers

• Nasopharyngeal Carcinoma: It is a type of cancer that occurs from the outer lining membrane of the nasal cavity and pharynx. This accounts for approximately 33.3 percent of all cancers that occur in the upper airways in pediatrics. This type of cancer is mostly associated with Epstein-Barr virus (EBV) infection. Due to its rich lymphatic drainage, it can invade adjacent areas, including the skull base, and can lead to trismus (difficulty in opening the mouth) and cranial nerve palsy.

• Esthesioneuroblastoma: It is also known as olfactory neuroblastoma, which is a small round cell tumor (a type of soft tissue tumor) that originates from the nasal neuroepithelium. The neuroepithelium is the specialized tissue in the nasal cavity responsible for the sense of smell. This type of tumor accounts for 28 % of pediatric cancer cases.

• Thyroid Tumors: It is a type of cancer that occurs in the thyroid gland, which is located in the front of the neck. These cancers are less aggressive compared to those in adults. This type of cancer accounts for 1.5 % of pediatric cancer cases and is more common in females.

• Oral Cavity Cancer: It is an extremely rare cancer, with the most common type being squamous cell carcinoma. This cancer affects the outer layer of the oral cavity, including the gums, tongue, palate, lips, and inner lining of the cheeks. It accounts for 0.6 % of all pediatric cancer cases.

• Salivary Gland Tumors: These cancers affect the salivary glands, which produce saliva. They mostly occur after chemotherapy or radiation therapy. The parotid gland is the most commonly affected gland. Children may present with painless swelling or lump near the face or neck region. This accounts for 0.5 % of all pediatric cancer cases.

• Laryngeal Cancer: These are cancers that develop in the larynx, which is the voice box located in the front of the throat. Risk factors for these cancers include certain genetic disorders and environmental factors such as exposure to secondhand smoke. Symptoms may include hoarseness in the voice, a lump in the throat, and difficulty in swallowing.

• Papillomatosis: It is a rare type of cancer characterized by benign growths in the respiratory tract, including the larynx. These growths are commonly observed after human papillomavirus (HPV) infection.

2. Thoracic Cancers

• Breast Cancer: These cancers are mostly seen in children who are 18 or younger. More than 95 percent of pediatric patients are female. Most females present with a lump in the breasts, breast asymmetry, nipple discharge, and enlargement of one breast compared to the other.

• Lung Cancer: This is an extremely rare type of cancer, with the most common type being pleuropulmonary blastoma. This cancer occurs in the lining of the lung called the pleura. The causes of this cancer can include genetic predisposition, inherited conditions, or environmental factors such as exposure to secondhand smoke.

• Esophageal Cancer: The most common types of tumors include squamous cell carcinomas. The risk factors for these tumors include caustic ingestion (ingestion of corrosive substances) and Barrett's esophagus, which occurs due to chronic exposure to stomach acid. Affected children may present with swallowing difficulties and associated weight loss.

• Cardiac Tumors: These cancers are extremely rare, accounting for about 0.001 to 0.30 percent of all cancer cases. The tumors can occur in various parts, such as heart valves, myocardium (the muscles of the heart), or endocardium (the lining of the heart). Common symptoms include abnormal heart rate, shortness of breath, heart murmurs, cyanosis (bluish discoloration of the skin), chest pain, and weight loss.

3. Abdominal Cancers

• Adrenocortical Carcinoma: These are types of cancers that affect the adrenal glands, which are located on top of the kidneys and are responsible for various body functions. They account for 0.2 percent of all pediatric cancers. These cancers are more aggressive in children compared to adults and have a poor prognosis.

• Gastric Cancer: It is also known as stomach cancer, accounting for 0.11 % of gastric cancer cases. The risk factors include genetic factors and infectious agents such as Helicobacter pylori (H. pylori) infection. Symptoms may include weight loss, vomiting, fatigue, anemia, bloating, and poor appetite.

• Pancreatic Cancer: These cancers are divided into two categories. Exocrine pancreatic tumors, which occur in the exocrine cells of the pancreas responsible for producing digestive enzymes like insulin, and pancreatic neuroendocrine tumors (PNETs), which arise from the specialized neuroendocrine cells of the pancreas that produce hormones.

• Colorectal Cancer: These account for about five percent of all cancers in pediatric patients. The primary risk factors are genetic predisposition and inherited conditions such as familial adenomatous polyposis (FAP), which involves the formation of polyps in the lining of the intestine. Patients typically present with symptoms such as blood in the stool, rectal bleeding, cramping, anemia, and weight loss.

4. Genital or Urinary Tumors

• Bladder Cancer: These cancers develop as a result of exposure to chemotherapy (specifically alkylating agents) given to treat other cancers, such as leukemia. Genetic factors may also contribute to the development of these cancers. The most common presentation of this cancer is hematuria (blood in the urine), urinary infection, urgency, and frequent urination.

• Testicular Cancer (Non-germ Cell): This cancer accounts for about one percent to two percent of pediatric cancers. Non-germ cell testicular tumors include sex cord-stromal tumors, which arise from the cells of the testicles responsible for hormone production. The risk factors for these tumors include genetic predisposition and syndromes such as Peutz-Jeghers syndrome.

• Ovarian Cancer (Non-germ Cell): The most common types of ovarian cancers in children include sex cord-stromal tumors (arising from the hormone-producing cells of the ovary) and epithelial tumors (occurring in the lining cells of the ovary). These cancers are mostly seen in older children. Children may present with early puberty, abnormal bleeding, abdominal pain, and bloating.

• Cervical and Vaginal Cancer: These cancers involve the abnormal growth of cells in the lower part of the uterus called the cervix and vagina. The risk factors include genetic predisposition and exposure to Diethylstilbestrol (DES), a nonsteroidal estrogen drug. Children may present with abnormal bleeding, urinary problems, and pelvic pain.

5. Others: Other rare childhood cancers include childhood mesothelioma, which is a type of cancer occurring in the lining of the lungs or abdomen and is mostly caused by asbestos exposure. Skin cancer is also a rare type of cancer that can include melanoma, squamous cell carcinoma, and basal cell carcinoma. Another rare cancer is chordoma, which is a bone cancer that originates from the notochord, an important structure in the formation of the backbone.

What Is the Prognosis of Rare Pediatric Oncological Conditions?

The prognosis for rare pediatric oncological conditions can vary widely depending on the specific condition, its stage at diagnosis, the type of treatment available, and how well the child responds to treatment. Some rare pediatric cancers may have a more favorable prognosis, while others may be more challenging to treat. It is crucial to consult with a pediatric oncologist who specializes in the particular condition to get the most accurate and up-to-date information about the prognosis and available treatment options for a specific case. Early diagnosis and access to advanced medical care can significantly impact the prognosis for children with rare pediatric oncological conditions.

Conclusion:

Rare pediatric oncological conditions present unique challenges in terms of management and diagnosis. This rarity can lead to a delayed diagnosis and limited treatment options. Treating cancers in children requires a multidisciplinary team, including surgeons, radiologists, pathologists, radiation oncologists, psychologists, and nurses, who can provide the utmost care to pediatric patients.