Hydronephrosis refers to extra urinary fluid in the kidney. Not a separate disease, but a physical phenomenon that occurs with many diseases, its symptoms, treatment, and prognosis are those of the disease that has caused it.

Hydronephrosis can be caused by obstruction of the ureters or bladder outlet. It can also result from reflux (retrograde passage of urine from the bladder up the ureters to the renal pelvis.)

Tumors of the kidney require surgical excision as well as combined management with pediatric oncology. 

• Wilms' tumor (the most common)
• Mesoblastic nephroma 
• Neuroblastoma, found commonly in the adrenal gland, but can be found anywhere along the sympathetic nervous system.

Sign/symptoms of kidney tumors include: 

• Abdominal pain
• Abdominal mass
• Blood in the urine
• Vomiting
• Failure to thrive (among others). 

The prognosis for these tumors has improved greatly with the combination of surgery, chemotherapy and radiation.

Kidney stones in children are far less common than in adults. The first step of treatment is to find out what type of stone is present. Stone types include:

• Calcium oxalate
• Uric acid
• Cystine stones
• Struvite stones. 

Once the type of stone has been discovered the cause of the stone formation needs to be identified. 

Kidney stones are frequently caused by inborn errors of metabolism, reflux and obstruction.

Often urinary tract infection (UTI) is the first sign of a congenital bladder or kidney anomaly. These UTIs may go undiagnosed if there is not a proper examination of the urine. If a true UTI exists then renal and bladder ultrasound as well as a VCUG should be performed to rule out any renal or bladder anomalies. Thirty to forty percent of children with a UTI accompanied by a high fever will have some type of urologic anomaly from birth.

Signs and symptoms of UTIs include:

• Dysuria (burning on urination) 
• Urinary frequency
• Urinary urgency 
• Foul smelling, cloudy urine 
• Incontinence (bed wetting episodes) 
• Fever

Vesicoureteral reflux is is an abnormal movement of urine from the bladder into the kidneys.

There are 5 grades of reflux - 1 is the mildest and 5 is the most severe.

Most children develop grade 1-2 reflux, which fortunately resolves itself over time in the majority of cases. Grade 3 will resolve approximately 50% of the time and grade 4 and 5 will resolve in a minority of cases.

The surgery to correct reflux essentially lengthens the path of the ureter as it travels into the bladder. The surgery is successful approximately 98% of the time, children usually going home in 2-3 days.

In an attempt to correct reflux without the need for traditional surgery, the Mount Sinai Division of Pediatric Urology is investigating a new cystoscopy procedure wherein a material is injected through a cystoscope to alter the ureter's opening in the bladder.

Prune belly syndrome is an extremely unusual condition. This occurs in males who have a wrinkled abdominal wall as a result of absence of abdominal musculature, bilaterally undescended testes, and othe rurinary tract anomalies, including an extremely large bladder and severe reflux with dilated ureters and varying degrees of dysplasia of the kidneys. 

Prune Belly syndrome is diagnosed at birth.

Exstrophy is an uncommon congenital bladder anomaly, bladder exstrophy results when the tissue making up the abdominal wall is deficient and the bladder is a flat sheet on the abdominal wall instead of a sphere inside the pelvis. Urine leaks out of the abdominal wall from the exposed ureteral orifices. This is associated with pubic separation and epispadias, which is a severe congenital curvature and foreshortening of the penis.

Posterior urethral valves are wisps of tissue in the prostatic urethra preventing the release of urine out of the urinary bladder. Ranging from a mild obstruction to very severe, resulting in renal failure, bladder dysfunction and even death. These problems are diagnosed increasingly by prenatal ultrasound. If done so, the goal of treatment is to obliterate these valves via a cystoscope within the first week of life. Attention should be directed to the possible electrolyte abnormalities as well as possible pulmonary hypoplasia (underdevelopment of the lungs) that may have developed secondary to the oligohydramnios (decreased amniotic fluid).

Neural tube defects occur when the bones of the spine do not correctly form, leaving the spinal cord and its nerves and coverings to protrude out through the skin (or lie just beneath it). The use of folate vitamins during pregnancy has decreased the incidence of neural tube defects. However many children still suffer from myelodysplasia (which includes myelomeningocele, occult spina bifida, etc). Since the bladder and the urinary sphincters function under neurologic control from the spinal cord, damage to the spinal cord can result in lower urinary tract dysfunction which, if untreated, can lead to renal damage.

Frequent infections, incontinence, and urinary frequency are common symptoms of neural tube defects.

Hypospadias -The most common genital abnormality seen by pediatric urologists are hypospadias abnormalities. In this condition the urethral opening is not at the tip of the penis but further down on the ventral surface (i.e., between the head of the penis and the scrotum). Often this abnormality is associated with chordee, a curvature of the penis down towards the scrotum. Surgical repair is recommended for those children whose hypospadias will affect future fertility, sexual intercourse, cosmesis and the ability to void in the standing position. The cause of hypospadias is not exactly known.

Episadias - Epispadias includes a severe dorsal curvature of the penis up towards the abdominal wall as well as the urethral opening near the surface of the abdomen. It is usually associated with bladder exstrophy.

Chordee - A chordee is a curvature of the penis. Some children are born with a chordee without associated hypospadias or epispadias.

Male/Female Genitalia - During development, both the male and the female external genitalia arise from the same common primitive structures. Their development into clearly recognizable male and female genitalia can be disrupted by any abnormality of chromosomes, gonadal problems or enzymatic disorders. Therefore children with XY genes can appear to have female genitalia and conversely children with XX genes can appear to have male genitalia.

Undescended testicles - One of the most common conditions that the pediatric urologist deals with is the undescended testicle. Originally forming in the retroperitoneum (the back part of the abdomen) and then descending to the inguinal canal and then into the scrotum, the undesended testicle occurs in. nearly 3 percent of all children born.  A good portion of these children will have the testis descend into the scrotum within the first year of life. 

Inginual hernia - Inguinal hernias occur quite commonly in the pediatric age group. These hernias differ from adult hernias in that the peritoneum (the sack that encompasses the intestines) fails to seal. Therefore communication exists between the abdomen and the scrotum.  Signs and symptoms of a hernia are that there is a bulge in groin or scrotum that often changes in size.

Hydrocele - A hydrocele is a collection of fluid along the membrane covering the front and sides of the testicle.

The difference between a hernia and a hydrocele: If the fluid from the peritoneum travels through this opening then the child has a hydrocele. If intestinal contents travel into the scrotum then the child has a hernia. They are essentially the same pathologic condition. They differ from adult hernias which are usually a disorder that arises from muscle weakness.