Editing Pediatrics: Anomalies of the Kidneys (section)

== Anomalies of the Collecting System ==

=== Calyceal Diverticulum ===
* A calyceal diverticulum is a cystic cavity within the kidney that is lined by urothelium and communicates with a calyx or, less commonly, with the renal pelvis through a narrow isthmus.
* The incidence based on excretory urography is ≈4.5 per 1000
* '''Upper calyx most frequently affected'''
* Small diverticula are usually asymptomatic
* Infection, milk of calcium or true stone formation are complications of stasis or obstruction that can produce symptoms
* The diagnosis is suggested on ultrasonography but is confirmed on CT scan or MRU
* '''Patients who are asymptomatic do not require treatment but should be followed periodically with ultrasonography.'''
* Laparoscopy by a retroperitoneal approach for marsupialization of the diverticulum, fulguration of the epithelial lining, and percutaneous marsupialization/ablation are treatment options.

=== Hydrocalycosis ===
* Hydrocalycosis is a rare cystic dilation of a major calyx with a demonstrable connection to the renal pelvis

=== Megacalycosis ===
* '''Megacalycosis is defined as nonobstructive enlargement of calyces resulting from malformation of the renal papillae'''
* '''The calyces are generally dilated and malformed and may be increased in number.'''
* '''The renal pelvis is not dilated,''' nor is its wall thickened, and the ureteropelvic junction is normally funneled without evidence of obstruction. The ureter is usually normal.
* '''Occurs predominantly in males''' with a ratio of 6:1 and '''has been found only in Caucasians'''.
* '''Bilateral disease has been seen almost exclusively in males, whereas segmental unilateral involvement occurs only in females'''
* Diuretic renography shows a normal pattern for uptake and washout of the isotope
* Long-term follow-up of patients with this anomaly does not usually show progression of the anatomic or functional status of the kidney

=== Infundibulopelvic Stenosis ===
* Most likely forms a link between cystic dysplasia of the kidney and the grossly hydronephrotic kidney.
* Usually bilateral and is commonly associated with vesicoureteral reflux, suggesting an abnormality of the entire UB