bubble_chart Overview

Subcutaneous nodules of the male reproductive system are a common condition, often coexisting with subcutaneous nodules of the urinary system. According to literature statistics, the concurrent occurrence of subcutaneous nodules in both systems ranges from 50% to 80%, while isolated subcutaneous nodules of the male reproductive system account for only 10%.

bubble_chart Pathogenesis

There are two routes of infection for male genital subcutaneous node:

1. Hematogenous infection: The pathogenesis of male genital subcutaneous node is similar to that of renal subcutaneous node, both being secondary sexually transmitted disease changes from subcutaneous node lesions in other organs of the body. The subcutaneous node bacillus invades the male genital system through the bloodstream.
2. Urinary tract infection: On the basis of renal subcutaneous node, the subcutaneous node bacillus invades the male genital system through urine, thus also representing a secondary sexually transmitted disease change of renal subcutaneous node. Moreover, the more severe the renal subcutaneous node lesions, the higher the likelihood of concurrent male genital subcutaneous node. In a series of 143 cases of renal subcutaneous node, foxtail millet-like renal subcutaneous node was complicated by male genital subcutaneous node in 13% of cases, caseous renal subcutaneous node in 58%, and cavitary renal subcutaneous node in 100%.

Currently, it is believed that male genital subcutaneous node, whether through hematogenous or urinary tract infection, often starts in the prostate and seminal vesicles before spreading to the vas deferens. From the lumen or lymphatic vessels of the vas deferens, it then spreads to the epididymis. After lesions develop in the tail of the epididymis, they extend to other parts of the epididymis and the testis. Hematogenous infection of the male genital tract subcutaneous node can directly cause epididymal subcutaneous node, with such infections typically starting in the head of the epididymis. Clinically, urinary tract infections are more common, while hematogenous infections are relatively rare.

bubble_chart Pathological Changes

The condition primarily involves the formation of subcutaneous nodules and caseous necrosis in the reproductive organs, including the prostate, seminal vesicles, vas deferens, and epididymis. After the expulsion of caseous material, cavities may form, or fibrosis can lead to the development of masses. Subcutaneous nodules in the prostate may occasionally rupture into surrounding tissues, forming sinuses in the perineal region. Subcutaneous nodules in the vas deferens can cause thickening and hardening, resulting in a beaded appearance. Epididymal lesions typically spread from the tail to the body and head of the epididymis and may extend beyond, forming cold abscesses that adhere to the scrotum. These abscesses may rupture and discharge pus, leading to chronic sinuses. Subcutaneous nodules in the epididymis can also spread to the testes, causing testicular subcutaneous nodules.

bubble_chart Clinical Manifestations

Male reproductive system subcutaneous nodes mostly occur in young adults, with domestic statistical data showing that 78% of patients are aged between 20 and 40. Male reproductive system subcutaneous nodes generally present as a slow sexually transmitted disease progression, often bilateral, but may appear sequentially during the course of the disease. Prostate and seminal vesicle subcutaneous nodes usually have no obvious symptoms and are often discovered during rectal examinations prompted by symptoms of epididymal subcutaneous nodes, revealing infiltration and hard nodules in the prostate and seminal vesicles. Destruction of the prostate parenchyma can reduce semen volume, thereby lowering or even eliminating fertility, with some cases exhibiting symptoms of hemospermia.

The clinical manifestations of male reproductive system subcutaneous nodes often resemble those of epididymal subcutaneous nodes, with slow progression and mild symptoms. The epididymis gradually enlarges, occasionally accompanied by a dragging sensation or mild dull pain, which may go unnoticed by the patient, leading to incidental discovery. The epididymal lesions spread from the tail to the body and head, eventually involving the entire epididymis. As the disease progresses, it may adhere to the scrotum and form caseous necrosis, leading to cold abscesses that eventually rupture into sinuses, becoming chronic and difficult to heal. A few cases of epididymal subcutaneous nodes may present with acute symptoms due to secondary infections, including sudden fever, redness, swelling, and pain in the scrotal epididymis, forming abscesses that rupture. After the acute symptoms subside, the condition transitions back to a chronic stage. The manifestation of vas deferens subcutaneous nodes is merely fibrosis-induced thickening and hardening, appearing cord-like or beaded. Bilateral vas deferens and epididymal subcutaneous nodes can lead to infertility.

bubble_chart Diagnosis

The diagnosis of male genital tract subcutaneous node is generally not difficult, primarily based on the aforementioned clinical manifestations, scrotal physical examination, and digital rectal examination. Irregular enlargement of the prostate and seminal vesicles, the presence of subcutaneous node nodules, as well as nodules in the epididymis and beaded thickening of the vas deferens, are all signs that can confirm the diagnosis. Epididymal lesions adhering to the scrotum and ulcerating to form a chronic sinus further confirm subcutaneous node pathology. For cases where the diagnosis remains unclear, semen culture or smear examination for subcutaneous node bacilli, as well as prostate fluid examination for subcutaneous node bacilli, can be performed. Although the chance of positive results is low, these tests still hold reference value. X-ray examinations may occasionally reveal calcification in the prostate. Seminal vesiculography can demonstrate lesions in the vas deferens and seminal vesicles, such as stenosis, obstruction, irregular contrast filling, dilation, or destruction. However, in many cases, the contrast agent fails to pass due to obstructive lesions, resulting in unsuccessful imaging, thus limiting its practical application value.

The diagnosis of male genital tract subcutaneous node also requires differentiation from prostate cancer, gonococcal or nonspecific epididymitis, and scrotal filariasis. Generally, this is not difficult and can be clarified through medical history, laboratory tests, and puncture biopsy.

When diagnosing male genital tract subcutaneous node, the relationship with the urinary system must be emphasized. Concurrent renal subcutaneous node may exist without urinary symptoms, making male genital tract subcutaneous node the only clue. Therefore, routine urine examinations for subcutaneous node bacilli are necessary, and systematic urinary system examinations should be performed when needed to clarify the diagnosis.

bubble_chart Treatment Measures

The treatment of male genital system subcutaneous node must include systemic treatment and treatment of the male genital system. Systemic treatment is the same as that for general subcutaneous node disease. The treatment of the male genital system includes both drug therapy and surgical treatment:

(1) Drug Therapy

Male genital system subcutaneous node responds well to anti-subcutaneous node drugs. Both prostate and seminal vesicle subcutaneous nodes can be treated conservatively with medication. The drug treatment method is the same as that for renal subcutaneous node, primarily involving the combined use of two or three drugs, such as isoniazid, streptomycin, and rifampicin. The typical treatment course is 6 to 12 months based on clinical experience.

(2) Surgical Treatment

Surgical treatment for male genital system subcutaneous node primarily addresses epididymal subcutaneous node. Resolving epididymal subcutaneous node aids in the healing of subcutaneous nodes in other parts of the genital system (seminal vesicles, prostate). The surgery is performed after the epididymal lesions are localized, similar to renal subcutaneous node, and anti-subcutaneous node drugs are required before and after the surgery.

Indications for epididymectomy:

1. Unilateral epididymal subcutaneous node.
2. Unilateral epididymal cold abscess formation.
3. Bilateral epididymal cold abscess formation.
4. Unilateral epididymal scrotal chronic sinus formation.
5. Bilateral epididymal scrotal chronic sinus formation.

During epididymectomy, the cut end of the vas deferens should be severed as high as possible and transplanted subcutaneously to prevent retraction and avoid the formation of subcutaneous node abscesses in the scrotum due to residual subcutaneous node lesions in the vas deferens. During epididymectomy, the testis should be preserved as much as possible. If the testis is already affected by the lesion, the affected portion of the testis should be excised to preserve partial testicular function. If the lesion has involved most of the testis and the testis cannot be preserved, the testis may be excised entirely.

There is no consensus on the management of the contralateral vas deferens during epididymectomy. For patients with aspermia detected in preoperative semen analysis, it is advisable to ligate the contralateral vas deferens.