Ureterocele, also known as ureteral cyst, ureteral bulge, and cystic dilatation of the lower ureter, is a cystic dilatation of the terminal ureteral tissue under the mucosa of the bladder. The ureteral orifice cyst structure has an outer layer of bladder mucosa, a middle layer of muscle fibers and connective tissue, and an inner layer of ureteral mucosa. Etiology The etiology of ureteral orifice cysts is still unclear, but most scholars believe that its occurrence may be related to the following causes: (1) delayed rupture of Chwalle’s membrane between the ureteral bud and urogenital sinus during embryonic life, resulting in dilatation of the ureteral end and narrowing of the ureteral opening; (2) abnormal differentiation of the ureteral bud. Delayed separation of the ureteral bud from the mesonephric duct resulted in dilatation of the ureteral end; (3) Stagnant embryonic development of the distal ureteral tissue. Compared with the proximal ureter, the lack of muscle bundles and the small size of myocytes in the bulging part of the ureteral orifice cyst and the absence of thick myogenic fibers in the muscle suggest that the muscle development of the distal ureteral tissues may have been arrested during embryonic development; ④ inflammation and trauma may have formed narrowing of the ureteral opening, resulting in the prolapse of the ureter into the bladder and the formation of the ureteral orifice cyst. Ma Honggui, Department of Urology, Affiliated Hospital of Guizhou Medical University Diagnosis According to the location of ureteral orifice cysts, they can be divided into simple type (15%) and ectopic type (80%). Simple type ureteral orifice cysts are located completely in the bladder, slightly offset from the normal position of the ureteral orifice, and are small in size, mostly seen in adults. Ectopic ureteral orifice cysts are located in the bladder neck or posterior urethra, 40% are bilateral, 80% of ectopic ureteral orifice cysts are accompanied by duplicated renal malformation, and they mostly occur in the ureter of the upper half of the kidney, thus often leading to dysplasia, hypofunction or non-function of the upper half of the kidney. Clinical manifestations (a) Urinary tract infection Ureteral orifice cysts are prone to secondary urinary tract infections with symptoms of fever, urinary frequency, urinary urgency and painful urination, and recurrent episodes. If the ureteral cyst opens in the urethra or perineum, purulent discharge can be seen at the urethral orifice or perineum when infection occurs. (B) Upper urinary tract obstruction Because ureteral orifice cysts easily cause vesicoureteral reflux, they often lead to ipsilateral ureteral dilatation and hydronephrosis. Ectopic ureteral orifice cysts of large size not only cause ureteral obstruction in the lower half of the ipsilateral duplicated renal malformation due to compression, but in a few cases may even compress the contralateral ureter, leading to upper urinary tract hydrophobia on the opposite side. Patients may clinically present with symptoms of lumbar distension and lumbar mass. (C) Difficulty in urination When ectopic ureteral orifice cysts are located in the bladder neck or posterior urethra, they may show dyspareunia, interruption of urine flow and urinary retention. In women, ectopic ureteral orifice cysts may prolapse through the urethra and appear as red mucosal cyst-like masses. (iv) Concomitant urinary stones Stones may be combined in the ureteral orifice cyst, which may present with renal colic and hematuria symptoms. Imaging tests (i) Ultrasonography (ultrasound) (recommended) Ultrasound is simple, economical, non-invasive and can be the preferred method for initial diagnosis and screening. ultrasound can provide information on the exact location, size and morphology of the ureteral orifice cyst within the bladder. The typical presentation of a ureteral orifice cyst on ultrasound is a round or oval cystic mass seen lateral to the bladder triangle with a uniform echogenic dark area within a thin wall and smooth edges, which can increase or decrease in size periodically with ureteral peristalsis. (B) Intravenous urography (IVU) (recommended) KUB+IVU is the most basic test to observe bilateral kidney and ureter and bladder, and to understand renal function and the presence of urinary tract malformations and stones. The typical presentation of an intravesical ureteral cyst IVU is an elliptical or circular solid shadow at the end of the ureter, surrounded by a transparent ring, in the form of a “cobra head” or a spherical shadow. (iii) Voiding cystourethrography (VCUG) (optional) Voiding cystourethrography can determine the size and location of the ureteral orifice cyst, as well as the presence or absence of vesicoureteral reflux, and it is important to determine the presence and extent of urinary reflux in order to choose the treatment. (iv) Cystoscopy (optional) Cystoscopy shows a spherical or oval cyst near the ureteral orifice on the affected side, with smooth surface of the cyst wall, clear blood vessels, and rhythmic filling and atrophy of the cyst. If the ureteral orifice is poorly visualized, intravenous indocyanine helps to visualize the ureteral orifice. Since the ureteral orifice cyst can become smaller with the increase of intravesical pressure, there is a possibility of missing the diagnosis, and cystoscopy should be used as an adjunct to the diagnosis. (E) Magnetic resonance water imaging (MRU) (optional) Because MRU has multidimensional scanning and reconstruction features, it can clearly show the whole urinary tract, which is especially suitable for examining the causes and sites that cause structural changes in the kidney and ureter, but it is expensive. MRU can clearly show ureteral orifice cysts and duplicated renal malformations, especially for patients with ectopic ureteral orifice cysts and poorly developed kidneys with duplicated renal malformations. can provide an accurate picture of the upper urinary tract, which is important for surgical selection. Treatment The treatment plan should be selected based on the patient’s age, volume of ureteral orifice cyst, cyst type, whether it is combined with duplicated renal malformation, renal function, and the presence of vesicoureteral reflux. The principles of treatment are to relieve obstruction, protect renal function, prevent infection and prevent vesicoureteral reflux. I. Treatment of simple ureteral orifice cyst II. Treatment of ectopic ureteral orifice cyst