Etiology
1.True prostate cysts
The prostate gland is obstructed during embryonic development, causing narrowing of the prostate ducts, resulting in obstruction and gradual retention of the contents, so it is a retention prostate cyst.
2, congenital cysts
The cyst is formed by the abnormal development of the middle renal duct and the middle paranephric duct and the partial expansion of the duct lumen. The cysts that originate from the parametrial duct are often located in the middle of the posterior prostate, while the cysts that originate from the parametrial duct are located at the sides. These cysts do not actually originate in the prostate gland and often adhere to the posterior bladder wall. The size of the cyst can often grow to be so large that pressure on the bladder neck causes difficulty in urination and pressure on the rectum causes a feeling of anal swelling and difficulty in defecation. The congenital prostate cyst is often accompanied by congenital diseases such as hypospadias, cryptorchidism and renal insufficiency.
3. Acquired cysts
It is caused by incomplete or intermittent obstruction of the glandular follicles due to the tough prostate stroma, which gradually thickens the epithelium of the glandular follicles and eventually leads to retention cysts, which can be located anywhere in the prostate or protrude into the bladder neck, with a diameter of 1 to 50px.
4, inflammatory cysts
It is a chronic inflammation of the prostate that causes the connective tissue to proliferate, leading to narrowing of the prostate duct and retention of secretions to form cysts.
5. Parasitic cysts
The cysts are caused by parasites, such as worms that can cause chronic inflammation in and around the prostate ducts; or by granulomas that gradually form cysts.
The above-mentioned cysts are most common in retained prostate cysts, which can occur in any part of the gland.
Clinical presentation
Prostatic cysts consist of normal glandular vesicles, or are multi-housed, with vesicles lined with columnar epithelium, some with low cuboidal epithelium, and the vesicles are filled with plasmacytic or plasma blood fluid. Prostate cysts can be complicated by infection and stones, and larger cysts can obstruct urine flow when they grow and press against the urethra or bladder neck. Common symptoms include urinary urgency, frequent urination, straining to urinate, thin urine line, urinary retention, etc. When pressed against the rectum, it can cause difficulty in defecation. If the cyst is large, the cyst can be palpated in the prostate on rectal examination.
Examination
1.Cystoscopy
A semicircular, or tipped, round, transparent mass with a diameter of 1 to 50 px can be seen protruding from the neck of the bladder. Most of them are acquired cysts.
2.X-ray examination
(1) Intravenous urography Can detect urinary tract abnormalities, such as renal dysplasia, etc.
(2)Urethrography No abnormal finding because the cyst is not connected with urethra and is not shown.
3.B-type ultrasonography
A round or oval transmissive area with smooth inner wall, clear edges and no internal echogenicity can be found in the prostate area. Transrectal ultrasound shows a well-defined, round, echogenic area extending from the center of the prostate to the upper posterior, in the shape of a teardrop, connected to the seminal frenulum by a small tip.
4.CT examination
A large cyst of the prostate and a Mullerian duct cyst are located in the posterior midline of the prostate and are round, well-defined cystic lesions with a watery density.
5, rectal or perineal puncture
If the cyst is too large, the cystic fluid can be extracted by rectal or perineal puncture. Acquired cysts are clarified mucus, or may be dark brown or bloody, and the cyst fluid may contain sperm.
Diagnosis
Pathological changes in prostate cysts can be diagnosed by pathological sections of the cysts. Understanding the mechanism of prostate cyst formation can be very helpful in the diagnosis of prostate cysts.
Treatment
Smaller asymptomatic cysts do not need to be treated, while larger cysts or small symptomatic cysts can be treated surgically via transcystal, extracystal, perineal, transrectal and other routes. Surgical excision is often incomplete due to poor exposure, with a high recurrence rate and many complications. Surgical resection of cysts near the perineum by trans-perineal approach is likely to cause ED and should be used with caution in young patients. There are reports of trans-perineal or trans-rectal cyst puncture and aspiration under ultrasound positioning, followed by injection of coagulant, but they are prone to recurrence.
Cysts near the urinary bladder or protruding into the bladder are removed with transvesical surgical resection or transurethral electrodesiccation to remove most of the top of the cyst to allow adequate drainage. Laparoscopic resection of prostate cysts has the advantages of clear tissue exposure, short operative time, less damage to pelvic tissues, less trauma, no fistula, less bleeding, etc. It is the preferred method for treating prostate cysts that protrude toward the back of the urethra and bladder neck.
For cysts near the urethra or protruding into the bladder, transurethral electrical resection of the cyst is the best route for the procedure, but in younger patients, preservation of the seminal caruncle is essential for normal ejaculation. When a patient has persistent high fever, no significant improvement in urinary symptoms, overflowing pus from the urethra, and poor bowel movement, the possibility of a prostate cyst should be considered and treated with abscess incision and drainage or puncture and drainage with the help of ultrasound and other tests to confirm the diagnosis. Only when the abscess is completely eliminated, the above symptoms will be relieved.