Emergency identification of scrotal swelling and gangrene, and detailed explanation of congenital testicular developmental abnormalities.

The scrotum is part of the male reproductive organs. Scrotal diseases can cause infertility, and in severe cases, they can be life-threatening. They should not be taken lightly. There are many causes of scrotal swelling, which can be summarized as follows: (1) Scrotal skin diseases: These are mostly skin edema (such as scrotal elephantiasis caused by filariasis), inflammation, trauma, blood stasis, and scrotal skin diseases. They are generally easy to diagnose. A urologist can be consulted to treat the different causes. (2) Hydrocele: This can cause typical scrotal swelling. Early and mild hydrocele may not require treatment and may heal on its own. Larger hydrocele can affect the blood circulation of the testes, causing testicular atrophy and even infertility. In this case, surgical treatment should be performed. (3) Varicocele: This refers to the dilation and tortuosity of veins that accompany the spermatic vein, vas deferens, and cremaster muscle. 98% of varicocele occurs on the left side. According to statistics, 10% of men aged 10 to 25 have varicocele, which is one of the causes of male infertility. Varicocele on the right side should raise suspicion of a right kidney tumor. The varicose veins usually disappear when the patient is lying down. Varicocele may be asymptomatic in mild cases, but may cause a feeling of heaviness or pain in severe cases, which worsens with activity. In a few cases, it can cause testicular atrophy and infertility. Surgical treatment is an option. (4) Seminal vesicle cyst: This condition mostly occurs in men aged 30 to 40. The cyst fluid contains fat, cell debris and sperm, which can cause cystic degeneration of the epididymis. This disease is mostly asymptomatic and harmless. Those with symptoms can be treated surgically. (5) Epididymitis: This is the most common disease in the scrotum, mostly occurring in young adults. It is also a complication of prostate surgery and long-term catheterization for urethral stricture. During an acute attack of epididymitis, the local scrotal skin is red and swollen, with obvious tenderness, and even systemic fever. In chronic cases, there is only mild pain or a feeling of heaviness on the affected side. A hard mass can be felt in the lower back of the testis in the scrotum. Tuberculosis is also common in chronic epididymitis. In the acute phase, antibiotics can be used to control infection. In chronic cases, chronic prostatitis is often treated at the same time. If tuberculosis is diagnosed, anti-tuberculosis treatment is given. If the epididymis is significantly enlarged, does not heal for a long time, and has obvious symptoms, the diseased epididymis can be removed. (6) Acute orchitis: In young people, acute orchitis is a common complication of mumps. In addition to treating the cause, estrogen can relieve symptoms, and traditional Chinese medicine is also very effective. (7) Testicular torsion: It mostly occurs in the tunica vaginalis of the testis. When it occurs, the testis suddenly experiences severe pain, often accompanied by collapse. The scrotum becomes red and swollen within 12 hours. If it lasts for a long time, it will affect the blood circulation of the testicular artery and cause infarction. Fluid and blood accumulate in the tunica vaginalis. Early patients can try manual reduction. After reduction, testicular fixation must be performed at the same time to prevent recurrence. If it is unsuccessful or there is obvious necrosis, the testis should be removed immediately. (8) Inguinal hernia: The mass extends from the scrotum to the groin. The mass may be visible or hidden, and its movement is related to body position. It appears when standing and applying abdominal pressure, and gradually disappears when lying down. When the hernia becomes incarcerated, its contents cannot be reduced, and blood supply is obstructed. At this time, there will be sudden abdominal pain, vomiting, and significant swelling of the scrotum. If the mass does not disappear, surgery should be performed immediately. (9) Testicular tumor: It is most common in people aged 20 to 40, and almost all of them are malignant. When the volume and weight of the testis increase, the possibility of a tumor should be considered. Once an accurate diagnosis is made, the tumor should be surgically removed or radiotherapy should be performed as soon as possible.

Sudden onset gangrene of the scrotum, though rare, is extremely dangerous and can occur at any age, but is particularly common in middle-aged and elderly men. The onset is rapid, sometimes even waking the patient from sleep at night. Symptoms primarily include: swollen, shiny, and itchy scrotal skin; pressing on it produces a crackling sound similar to rubbing hair; rapid necrosis, ulceration, and purulent discharge with a foul odor can occur. Necrosis is generally limited to the scrotal skin, but in some cases it can spread to the inner thighs, buttocks, or lower abdomen. Patients may experience systemic symptoms of poisoning such as chills and high fever, and may even develop toxic shock. The scrotal skin has many folds, making it easy for bacteria to accumulate. The subcutaneous tissue is loose, and due to local sweating or urinary infiltration, it is often moist. Combined with the fact that the perineum is hidden and not exposed, it is an ideal environment for bacterial growth and reproduction, leading to infection under certain conditions. Because sudden onset gangrene of the scrotum is dangerous, progresses rapidly, and has a high mortality rate, patients should seek medical attention as soon as possible after onset.

Sudden-onset scrotal gangrene is classified into primary and secondary types. Primary scrotal gangrene usually has no obvious cause; secondary scrotal gangrene is caused by local factors including: ① itching of the scrotal skin, leading to infection after scratching and damage. ② inflammation of the anus and rectum, such as infected hemorrhoids or ruptured perianal abscesses. ③ chronic prostatitis causing lower urinary tract obstruction, resulting in urine extravasation and infection. Systemic factors include diabetes, hypertension, stroke, malnutrition, and arteriosclerosis. Drug allergies also play a role; for example, a patient took compound sulfamethoxazole for frequent and painful urination. The next day, the glans penis and scrotum experienced itching, blistering, and weeping. Instead of stopping the medication, he applied sulfanilamide powder locally, resulting in severe necrosis of the penile and scrotal skin. Therefore, to prevent sudden scrotal gangrene, patients should promptly treat any underlying conditions such as hypertension, diabetes, and arteriosclerosis. If lower urinary tract obstruction leads to urine extravasation, patients should undergo cystostomy to drain urine. For those with anorectal inflammation, anti-infective treatment should be administered. Patients should also frequently wash the perineal area to keep it clean and dry. If severe itching occurs, medication should be used under the guidance of a doctor; avoid scratching the skin or self-medicating with oral or topical medications. Maintaining a balanced diet, regular bowel movements, and regular physical exercise are also important to strengthen the body and improve immune function.

Congenital testicular abnormalities are common in clinical practice and are developmental malformations present at birth. They can manifest as abnormalities in number, position, and size, such as unilateral testicular absence, bilateral testicular absence, polyorchidism, abnormal testicular descent, and cryptorchidism. (1) Unilateral testicular absence: Unilateral testicular absence is uncommon, accounting for about 0.4% of males, but it is more common than bilateral absence. It often occurs on the right side and is often accompanied by the absence of the ipsilateral kidney and ureter. About 20% of patients with cryptorchidism cannot have their testes palpable before surgery, and about 20% of patients whose testes cannot be palpable cannot have their testes found during surgical exploration. Testicular absence may be due to the lack of development of the gonads or due to fetal testicular torsion and vascular embolism in early pregnancy. Normal fetal testes secrete two hormones: one is testosterone secreted by interstitial cells, which causes the ipsilateral mesonephric duct to form the epididymis and ureter; the other is the mesonephric duct inhibitory factor secreted by Sertoli cells, which causes the mesonephric duct to degenerate and only remain as testicular appendages. Therefore, if there is no testis during surgical exploration, the epididymis, vas deferens, and spermatic cord may all be closed and blind or absent. In unilateral testicular absence, the spermatic cord is the most common site of blindness. (2) Bilateral testicular absence: The development of the fetal external genitalia requires stimulation from the androgens newly secreted by the fetal testes. If a normal male with a karyotype of 46,XY does not have testes, it indicates that after the formation of a normal male embryo (12-14 weeks of gestation), the testes degenerate and disappear for some reason. In bilateral testicular absence, even though gonadotropins are often elevated in early life, follicle-stimulating hormone (FSH) is elevated, but luteinizing hormone is not necessarily elevated before puberty. In normal boys of any age, the vast majority of testosterone levels will increase after the administration of human chorionic gonadotropin. Therefore, if both testes cannot be palpated, and follicle-stimulating hormone and luteinizing hormone are elevated, but testosterone does not increase after the injection of human chorionic gonadotropin, anorchia can be diagnosed, and surgical exploration is unnecessary. If the above conditions are not met (e.g., testosterone responds to human chorionic gonadotropin or testosterone does not respond to human chorionic gonadotropin, but gonadotropin levels are not increased), surgical exploration is required, and at least one testis should be present. (3) Polyorchidism: Congenital polyorchidism is a rare malformation, possibly due to the division of the gonadal crest in early embryonic development, where two testes may share a vas deferens, and it is often accompanied by undescended or torsion of the testis. However, in most cases, the additional testis has already descended, presenting as an asymptomatic mass in the scrotum. (4) Cryptorchidism: This refers to one or both testes stopping on their descent without entering the scrotum. In cryptorchidism, undescended testis is far more common than ectopic testis. Two-thirds of cryptorchidism cases are unilateral, and one-third are bilateral. Right cryptorchidism accounts for about 70%, while left cryptorchidism accounts for only 30%. In terms of location, the inguinal canal accounts for the vast majority (70%), the upper part of the scrotum accounts for 20%, and the abdominal cavity accounts for only 8%.

Why do the testes fail to descend into the scrotum as normal? The main process is regulated by the body's endocrine system. Human chorionic gonadotropin (hCG) secreted by the placenta stimulates the embryonic testes to produce testosterone, which is then converted to dihydrotestosterone (DHT) by enzymes, thus promoting testicular descent. Therefore, if the mother abuses estrogen or progesterone during pregnancy, the fetal testes will not secrete enough androgens. Various reproductive endocrine factors can cause an imbalance in the secretion of these hormones, affecting the testicular descent process. However, the main cause of cryptorchidism is related to local mechanical factors. For example, a short spermatic cord connecting the testes, narrowing or premature closure of the inguinal canal, absence of the gubernaculum testis (the ligament connecting the testis to the base of the scrotum), adhesions between the testes and surrounding tissues, scrotal hypoplasia, or the testes entering a "side path" instead of following the gubernaculum testis can all cause cryptorchidism. Some scholars believe that the condition of the testes themselves, such as insufficient development, also contributes to cryptorchidism. Therefore, the idea that one testicle has descended and everything is fine is extremely dangerous. Besides the threat of cancer in the undescended testicle, the descended testicle may also be underdeveloped, so early examination and treatment are essential.

Cryptorchidism has many harmful effects. It keeps the testicles at a relatively high temperature, preventing normal sperm production. Bilateral cryptorchidism can cause infertility due to azoospermia, with an incidence rate of 50%–100%. Unilateral cryptorchidism can affect the contralateral testicle, with an infertility rate of 30%–60%. If the testicle remains in the groin or pubic region, it is easily damaged due to pressure because of the lack of scrotal protection. The chance of developing tumors in cryptorchidism is 20–50 times higher than in normal individuals. Approximately 8% of patients with cryptorchidism will develop cancer. The peak age of onset is usually 25–35 years. Some have pointed out that repositioning the testicle after age 10 does not help restore fertility or reduce the possibility of malignancy. The psychological impact of not having a testicle in the scrotum, the inferiority complex caused by poor development of secondary sexual characteristics, and infertility after marriage can all cause severe psychological trauma to patients. Therefore, it is inappropriate to think that unilateral cryptorchidism is harmless and not seek timely treatment. Of course, bilateral cryptorchidism should be diagnosed and treated promptly in childhood.