Neuroblastoma
Neuroblastoma is a tumor that may arise at any site in the sympathetic nervous system, including the brain, neck (3%), chest next to the spine (20%), abdomen on either side of the aorta (24%), pelvis (3%), and adrenal gland (50%) (Figure 1). It is the second most common solid tumor of infancy and childhood, being exceeded only by brain tumors. More than 25% of cases are diagnosed before 1 year of age; 50% of cases by age 2 years, and 90% by age 8 years.

Omphalocele
An omphalocele is a covered defect of the umbilicus (belly button) with a “sac” which contains abdominal contents. The skin and the muscle of the abdomen are missing. This problem is thought to start in the third week of development when the intestines elongate and normally reside in the yolk sac outside of the abdomen. Omphaloceles are covered by a sac composed of an outer layer and an inner layer. The umbilical cord s right into the sac. A separate compartment containing a jelly-like material also may be observed. If the omphalocele is above the umbilicus there may be other defects involving the diaphragm, sternum, and heart. If the omphalocele is below the umbilicus there may be other defects affecting the bladder, rectum, and lower spinal cord.

Pancreas Divisum
Pancreas divisum results when the back of the pancreas drained by one pancreatic tube and the front of the pancreas drained by another tube fail to join before joining with the main bile tube. The chances of someone having pancreas divisum are believed to be 5% to 10%, but drainage is normal in most of these people without any site of blockage.

Pancreas Transplantation
Pancreas transplantation has been used rarely in children, but it is likely to be used more often in the future. This is because more recent improvements in immunosuppressive drugs and surgical technique have provided better results with fewer risks, and pancreatic cell (islet cell) transplantation is now being done. Pancreas transplantation is performed either as a single-organ transplant or at the same time as a kidney transplant in patients with severe kidney disease.

Pancreas Tumors
Malignant tumors of the pancreas are rare in infants and children. In most patients, by the time the diagnosis is made, a mass can be felt, and yellowing of the skin and eyes is often present. Patients with malignant pancreatic tumors range in age from 3 months to 16 years with most patients younger than 10 years old.

Pancreatic Cysts
Papillary neoplastic cysts, which are rare in childhood, should be assumed to cause cancer. Only by looking at the cyst under the microscope after surgery can doctors tell if the cyst is cancerous. They are easily ruptured, and the fluid inside the cyst is extremely irritating to the inside of the belly.

Pancreatitis
The pancreas is very important to a child’s normal growth and development. It sits in the back of the abdomen, behind the stomach and does two things: 1) It produces enzymes, which help with digesting food and 2) it produces hormones such as insulin and glucagon, which help control blood sugar. In the fetus and newborn baby, the pancreas produces almost no pancreatic enzymes (amylase and lipase); then, the child’s pancreas starts making these enzymes, which help in the digestion of food. Production of these enzymes is at full adult levels by age 2 years.

Parathyroid
There are four parathyroid glands along the behind the thyroid glands and near the edges of the gland. They are pea-sized and control calcium levels in the body. The most common disease of the parathyroid glands in children is hyperpararthyroidism.

Pectus Carinatum
Protrusion deformities of the anterior chest wall are 10 times less frequent than depression deformities. Associated disorders, including congenital heart disease, Marfan’s syndrome, spine abnormalities, and musculoskeletal defects are as frequent as in patients with pectus excavatum. The deformity typically is mild or absent in early childhood and becomes increasingly prominent during the rapid growth in early adolescence.

Pectus Excavatum
Pectus excavatum, or funnel chest, is a congenital malformation of the anterior chest characterized by a prominent depression of the body of the sternum, usually involving its lower half to two-thirds. The lower rib cartilages bend posteriorly to form a depression. The first and second ribs, and the upper sternum are essentially normal. Asymmetric deformities are common, with the depression being deeper on the right with the sternum being rotated posteriorly to that side. In most instances however, the depression is involves the lower half of the sternum and is symmetrical with a decrease in the depth of the chest cavity.

Perianal and Perirectal Abscess
Perianal abscesses (pus collection) and fistulas (tunnels that connect the inside of the anus to the skin outside) are seen commonly in male infants younger than 1 year of age with a peak incidence at 4 months of age.

Pyloric Stenosis
Pyloric stenosis is the most common disorder causing vomiting in infancy which requires surgery.

Short-Bowel Syndrome
There are numerous definitions for short-bowel syndrome (SBS). The simplest definition is that there is inadequate intestine to maintain normal nutrition by eating. Because infants and children require increased calories to grow and develop, SBS can have a more devastating effect in these patients.

Solid Chest (Medistinal) Tumors
Mediastinal tumors are fairly common in children and can be either benign (noncancerous) or cancerous (malignant). Approximately 60% are malignant. These tumors include Hodgkin’s disease, non-Hodgkin’s lymphoma, neurogenic tumors, thymomas, teratomas, lipomas, lipoblastoma, germ cell tumors, and other rare lesions.

Spleen Problems
he spleen was long believed to be an unnecessary organ that could be removed without causing any problems. Important functions of the spleen have now been discovered, however, including the removal of bacteria and waste from the blood, the making of antibodies, and the making of red blood cells.

Testicular Torsion
Torsion of Testicular Appendix Torsion of an appendix testis and appendix epididymis are common causes of torsion. Both of these are small tags of normal tissue attached to the testicle.

Thyroglossal Duct Cysts and Sinuses
Embryology: The thyroid gland, although situated in the lower portion of the neck around the trachea, originates in the mouth at the back of the tongue and then moves down the neck during development. As the thyroid gland moves down to its normal position, there is a connection to the base of the tongue that should disappear by the time the thyroid reaches its final position. If it does not, there may be a persistent hollow tube that may allow accumulation of mucoid material and the formation of a cyst at the end.

Thyroid Cancer
The frequency of thyroid cancer has increased since the 1960’s, and is one of the most common pediatric cancers.

Thyroid Nodules
A thyroid nodule is a lump found in the gland. They can be malignant (cancer) or benign (not cancer). Although thyroid nodules are more common in adults than children, they are more likely (20-30%) to be malignant in children.

Thyroid Tissue at the Wrong Site (Ectopic)
Ectopic tissue is normal tissue that is found in a part of the body where it is not usually meant to be. During normal development, the thyroid forms at the base of the tongue, and later drops down into the neck. A remnant is left behind which usually involutes (goes away). If the thyroid does not descend normally, it may remain at the base of the tongue (called a lingual thyroid) or within the muscles of the neck.