Male Reproductive System Diseases

The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. The prostate consists of multiple lobes and is made up of glandular and fibromuscular tissue. The glandular tissue has ducts that empty into the prostatic portion of the urethra, and the fibromuscular tissue encircles the urethra.

The urogenital system is derived from intermediate mesoderm. The intermediate mesoderm differentiates into nephrogenic cords (which will go on to form the urinary system) and an adjacent area known as the gonadal ridge (which will go on to form the gonads). The nephrogenic cords elongate in a caudal direction and sequentially develop 3 different structures: the pronephros (rudimentary and nonfunctional), the mesonephros (forms the primitive urinary system), and the metanephros (forms the permanent kidney). Concurrently, the genital system develops in close association with the urinary system. Genital development depends on chromosomal sex, which determines whether the primitive gonads differentiate into testes or ovaries. The gonads then secrete certain hormones, which direct further development of both the internal and external genital structures.

The testicles, also known as the testes or the male gonads, are a pair of egg-shaped glands suspended within the scrotum. The testicles have multiple layers: an outer tunica vaginalis, an intermediate tunica albuginea, and an innermost tunica vasculosa. The testicles are composed of testicular lobules (contain interstitial tissue) and seminiferous tubules (produce spermatozoa). Blood supply to the testicles is primarily provided by the testicular artery. Venous drainage is through testicular veins.

Bowen disease and erythroplasia of Queyrat are 2 related entities that describe squamous cell carcinoma (SCC) in situ of the skin. Bowen disease usually presents in sun-exposed areas (e.g., face and forearms) as a red, scaly skin lesion. The lesion can occur in other areas as well. The genital region, particularly the penile shaft, is also affected. When the glans penis is involved, the lesion is called erythroplasia of Queyrat, with uncircumcised males being at high risk. Both genital lesions have HPV infection as a risk factor. Pathologic findings show full-thickness atypia without basement membrane invasion. Both entities may progress to invasive SCC. Thus, local destruction via surgical excision or topical chemotherapy should be performed.

Bowenoid papulosis is a sexually transmitted condition induced by HPV infection, which facilitates keratinocyte neoplastic transformation. On skin biopsy, Bowenoid papulosis manifests as low-grade dysplasia. Affected individuals present with genital papules of a red-to-brown color that are often asymptomatic. Although most cases resolve spontaneously, lesions should be followed up because there is a risk of transformation to invasive squamous cell carcinoma (SCC). Cryosurgery, excision, or topical therapy may be used to hasten the resolution of persistent cases of Bowenoid papulosis.

Testicular cancer is the most common solid malignancy affecting men 15–35 years of age. Most of the testicular cancers are of the germ cell tumor type, and they can be classified as seminomas and nonseminomas. The most common presentation of testicular cancer is a painless testicular mass. Diagnosis is via physical exam, testicular ultrasonography, and serum tumor markers. Additional imaging helps with staging and assessment of metastasis. Treatment consists of surgical inguinal orchiectomy, and further adjuvant therapy is based on disease pathology and stage. Subsequent strategies include disease surveillance, radiotherapy, and chemotherapy. Disease prognosis is excellent, as testicular cancer is one of the most curable solid neoplasms.

Penile anomalies and conditions may be congenital or acquired and can affect the urethral opening, prepuce, shaft, or glans or the penis. Examples include phimosis, paraphimosis, epispadias, hypospadias, balanitis, Peyronie disease, and priapism. The severity of clinical symptoms varies, but diagnosis of each of these conditions is usually based on the history and physical examination. Treatment varies from medical therapies to surgical intervention. These diagnoses are important to be aware of, since a few (such as phimosis and balanitis) are relatively common, while others (such as paraphimosis and priapism) can have severe complications if not treated in a timely fashion.

The scrotum is a sac hanging outside the body that contains parts of the male reproductive system. The scrotum’s main function is to support testicles outside the body so that spermatogenesis can be completed under optimal conditions. The scrotum can be affected by various pathologic conditions, and imaging is a valuable tool in reaching the appropriate diagnosis. The most important imaging method is ultrasonography +/– Doppler mode because scrotal structures are superficial with no intervening gas. MRI is useful when ultrasound is indeterminate.

Malignant lesions of the penis arise from the squamous epithelium of the glans, prepuce, or penile shaft. Penile cancer is rare in the United States, but there is a higher prevalence in lower socioeconomic regions. The most common histologic subtype is squamous cell carcinoma. Uncircumcised men and those with HPV infections are at highest risk of penile neoplasms. Diagnosis is a combination of physical exam, history, imaging studies, and tissue biopsy. Proper TNM staging is necessary to determine the correct treatment, which ranges from local topical therapy to multimodal surgery/radiation/chemotherapy.

Benign or nonacute scrotal masses are represented by hydroceles, varicoceles, and spermatoceles. Key components to evaluation are physical exam and scrotal ultrasound. Hydroceles represent extra fluid in the tunica vaginalis, leading to a swollen scrotum. Varicoceles have a dilatation of the pampiniform venous plexus, giving the “bag of worms” appearance on exam. Spermatoceles present as an epididymal cyst, commonly arising from the head of the epididymis. Hydroceles, varicoceles, and spermatoceles are usually asymptomatic and do not require treatment unless they are causing pain or other complications.

Testicular torsion is the sudden rotation of the testicle, specifically the spermatic cord, around its axis in the inguinal canal or below. The acute rotation results in compromised blood flow to and from the testicle, which puts the testicle at risk for necrosis. Quick diagnosis and intervention is key to saving the affected testicle. Emergent surgical exploration with subsequent orchidopexy is required. Ultrasound or manual detorsion should not delay definitive care.

Prostatitis is inflammation or an irritative condition of the prostate that presents as different syndromes: acute bacterial, chronic bacterial, chronic prostatitis/chronic pelvic pain, and asymptomatic. Bacterial prostatitis is easier to identify clinically and the management (antibiotics) is better established. Whether the condition is in an acute or chronic state determines the length of antibiotic treatment. The main diagnostic tools are history, physical examination, and work-up investigating the sources of infection (urinalysis and culture). Digital rectal examination is only recommended in patients with chronic prostatitis and not in acute bacterial prostatitis due to the risk of sepsis. Chronic pelvic pain syndrome is a diagnosis of exclusion and requires multimodal pain management with established patient expectations. The asymptomatic type is an incidental finding that is recognized when a patient has other urologic issues.

Cryptorchidism is one of the most common congenital anomalies in young boys. Typically, this asymptomatic condition presents during a routine well-child examination where 1 or both testicles are not palpable in the scrotum. Diagnosis depends on physical exam and ultrasound is performed only when other disorders are suspected. Treatment is dependent on patient age and testis position. In boys with persistent undescended testis by age 6 months, the condition is unlikely to spontaneously resolve. If the testis is palpable but not in the dependent intrascrotal location, an orchiopexy (bringing the testicle to the scrotum) is preferred. If the testis is non-palpable, a diagnostic laparoscopy is needed to inspect for an intra-abdominal testis, which requires a staged Fowler-Stephen’s orchiopexy.