Testicular Disorders

Mechanical/ischemic

• Intravaginal torsion: congenital bell-clapper deformity — the tunica vaginalis inserts high on the cord, leaving the testis suspended like a clapper and free to rotate. Bilateral in most cases, which is why the AUA supports contralateral orchiopexy at exploration.
• Extravaginal torsion: neonates, whole cord and tunica twist; incidence is bimodal (perinatal and puberty, when testicular volume rapidly increases).
• Trauma, prior intermittent torsion, and cold weather/nocturnal cremasteric contraction are classic stem triggers.

Infectious/inflammatory

• Sexually transmitted epididymo-orchitis: Chlamydia trachomatis and Neisseria gonorrhoeae predominate in men under ~35 (CDC STI Treatment Guidelines).
• Enteric organisms (E. coli, Pseudomonas): older men, bladder outlet obstruction, recent instrumentation, or insertive anal intercourse.
• Viral orchitis: mumps in unvaccinated post-pubertal males; also HIV, EBV, coxsackie. Tuberculous epididymitis in endemic/immunosuppressed settings.

Vascular/venous

• Varicocele: incompetent internal spermatic vein valves; left-sided predominance because the left gonadal vein enters the left renal vein at a right angle (nutcracker physiology). A new or right-sided varicocele suggests retroperitoneal mass or renal cell carcinoma with IVC/renal vein invasion.

Neoplastic

• Germ cell tumors arise from germ cell neoplasia in situ; peak in ages ~15–40.

Non-modifiable risk factors

• Cryptorchidism — the single most tested association; risk persists in the contralateral descended testis.
• Prior contralateral germ cell tumor, first-degree family history, White race, gonadal dysgenesis/DSD, Klinefelter syndrome (primary hypogonadism; classically linked to mediastinal extragonadal germ cell tumors).

Modifiable/acquired

• Unprotected intercourse and untreated STI, exogenous anabolic-androgenic steroids (suppress LH/FSH → atrophy, azoospermia), alkylating chemotherapy and scrotal radiation, opioids and glucocorticoids (central suppression), obesity, and occupational heat or gonadotoxin exposure.
• Timely orchiopexy (AUA cryptorchidism guideline favors surgery in infancy) lowers—but does not eliminate—malignancy risk and improves fertility and examinability.

• Spermatogenesis disruption: Damage to germinal epithelium, Sertoli cells, or Leydig cells impairs testosterone production and sperm production; interruption at any stage (from spermatogonia through mature spermatozoa) reduces fertility
• Ischemic injury: Testicular torsion, trauma, or vascular compromise causes acute ischemia leading to germ cell apoptosis and permanent fibrosis if not rapidly reperfused; damage begins within 6 hours and becomes irreversible by 24 hours
• Inflammatory/infectious cascade: Viral (mumps, HSV, HIV) or bacterial pathogens trigger local inflammation, immune-mediated cell destruction, and potential autoimmune response against sperm antigens
• Hormonal dysregulation: Disruption of hypothalamic-pituitary-testicular (HPT) axis feedback impairs GnRH secretion, FSH/LH production, and subsequent testosterone synthesis
• Neoplastic transformation: Malignant degeneration from germ cell tumors (most common testicular malignancy in young men) or Leydig cell tumors alters normal tissue architecture and function
• Obstruction or dysfunction: Mechanical blockade (epididymitis, vas deferens obstruction) or ductal abnormalities prevent sperm transport despite normal production

• Acute testicular pain and swelling: Sudden onset severe pain, scrotal erythema, and enlargement in testicular torsion (typically adolescents) or acute epididymitis (sexually active males or older men with urinary obstruction); torsion is a surgical emergency
• Painless testicular mass: Hard, firm nodule within testicular tissue suggests testicular cancer; patients often discover incidentally or report dull ache; higher risk in cryptorchidism, family history, and Klinefelter syndrome
• Infertility and sexual dysfunction: Reduced ejaculate volume, decreased libido, or erectile dysfunction; may reflect chronic spermatogenesis disruption or low testosterone from hypogonadism
• Fever with urethral symptoms: Dysuria, urinary frequency, penile discharge, and scrotal pain indicate acute epididymitis; often preceded by UTI or STI exposure
• Inguinal pain radiating to testis: Classic presentation of inguinal hernia with testicular tenderness mimicking torsion; differentiate by palpating above scrotum
• Transillumination findings: Fluid collection (hydrocele or spermatocele) transilluminates; solid masses do not—critical for distinguishing benign from malignant pathology
• Absent cremasteric reflex: Eliciting this reflex (testis retracts when inner thigh is stroked) is absent in testicular torsion but present in epididymitis; highly sensitive and specific finding

• Clinical examination and cremasteric reflex: Physical exam combined with absent cremasteric reflex (>95% sensitive for torsion) guides emergent ultrasound; palpation of epididymis tenderness, urethral discharge, and urinary symptoms help differentiate epididymitis
• Scrotal ultrasound with color Doppler: First-line imaging; demonstrates testicular blood flow, echogenicity, masses, or fluid; in torsion shows absent or decreased blood flow; high sensitivity (90-100%) and specificity for acute pathology
• Serum tumor markers (for testicular cancer): AFP, hCG, and LDH rise in germ cell tumors; AFP elevated in non-seminomatous tumors, hCG in choriocarcinoma/embryonal subtypes; LDH nonspecific but prognostic
• Semen analysis: Low sperm count (oligospermia), decreased motility (asthenospermia), or abnormal morphology (teratospermia) indicate spermatogenesis dysfunction; baseline for infertility evaluation
• Serum testosterone and LH/FSH: Low testosterone with elevated LH/FSH indicates primary hypogonadism (testicular failure); low testosterone with low/normal LH/FSH indicates secondary hypogonadism (HPT axis dysfunction)
• Urinalysis and urine culture: Pyuria, bacteriuria, and positive culture support bacterial epididymitis; negative in viral orchitis
• CT or MRI staging (for testicular cancer): Once malignancy confirmed, stage with imaging to assess retroperitoneal lymph node involvement and distant metastases

• Testicular torsion—emergent surgical detorsion: Manual detorsion (external rotation) may temporarily relieve pain but urgent surgical exploration and bilateral fixation (suture orchiopexy) is definitive; salvage rate >90% if surgery within 6-8 hours, drops significantly after 24 hours; contralateral testis also at risk and should be prophylactically fixed
• Acute epididymitis—antibiotics and supportive care: Fluoroquinolone (e.g., levofloxacin 500 mg daily × 10-14 days) or doxycycline 100 mg BID × 10-14 days for sexually transmitted etiologies; add ceftriaxone if gonococcal infection suspected; supportive measures include bed rest, scrotal elevation, NSAIDs (ibuprofen 400-600 mg TID)
• Orchitis—antiviral and supportive care: Mumps orchitis managed with NSAIDs and supportive care (no curative antiviral); viral orchitis typically self-limiting; may develop hydrocele or atrophy in 30-50% of cases
• Testicular cancer—chemotherapy, radiation, and/or surgery: Management depends on tumor type and stage; seminomas (radiosensitive) treated with radiation or chemotherapy; non-seminomatous germ cell tumors typically require bleomycin, etoposide, cisplatin (BEP) chemotherapy; radical inguinal orchiectomy for all malignancies; retroperitoneal lymph node dissection if stage IIA-IIB
• Hypogonadism—testosterone replacement: Testosterone gel, patches, or injections (testosterone enanthate/cypionate 50-100 mg IM weekly or 200 mg every 2 weeks) for symptomatic primary or secondary hypogonadism; baseline PSA and hemoglobin; monitor for polycythemia, prostate disease
• Infertility management: Address reversible causes (infection, obstruction, varicocele); consider gonadotropin therapy (hCG or FSH) for secondary hypogonadism; assisted reproductive techniques (IVF) for azoospermia or low motility; varicocele repair may improve fertility outcomes

• Infertility and azoospermia: Permanent spermatogenesis failure from torsion (high risk if delayed treatment >24 hours), severe infection, or malignancy treatment (chemotherapy and radiation cause transient or permanent oligospermia); testicular atrophy follows ischemia in 50-70% of salvaged testes
• Hypogonadism and sexual dysfunction: Spermatogenesis recovers faster than Leydig cell function; chronic hypogonadism increases cardiovascular risk, osteoporosis, and depression; erectile dysfunction multifactorial from hormonal deficiency and psychological factors
• Metastatic disease and death: Testicular cancer with poor prognostic markers (elevated tumor markers, advanced stage, non-seminomatous histology) requires aggressive chemotherapy; relapse rates 5-10% even with treatment; late relapses occur in 1-5%
• Secondary malignancies: Radiation or chemotherapy for testicular cancer increases risk of secondary solid tumors (lung, gastric, esophageal) and hematologic malignancies; cumulative dose-dependent risk
• Testicular atrophy: Ischemic injury, chronic infection, or malignancy treatment leads to permanent testicular volume loss (>50%

• Torsion is a clinical diagnosis: high-riding, transversely oriented testis with absent cremasteric reflex and negative Prehn sign (no relief with elevation). The single best next step in a high-probability adolescent is immediate urologic consultation for scrotal exploration — Doppler ultrasound must never delay the operating room.
• "Blue dot sign": focal tenderness at the upper pole with a small bluish nodule = torsion of the appendix testis. Preserved flow on Doppler, managed with NSAIDs and reassurance — a common distractor written to look like torsion.
• AFP is never elevated in pure seminoma. If AFP is up, the tumor behaves as a non-seminomatous germ cell tumor regardless of biopsy wording. β-hCG may be mildly elevated in seminoma from syncytiotrophoblasts; markedly elevated hCG with gynecomastia suggests choriocarcinoma.
• Radical inguinal orchiectomy — never transscrotal biopsy (NCCN): scrotal violation seeds inguinal lymphatics and alters staging. Testicular lymphatic drainage follows the gonadal vessels to retroperitoneal para-aortic nodes; scrotal skin drains to inguinal nodes.
• Histology buzzwords: Schiller-Duval bodies (yolk sac, AFP, most common testicular tumor in boys under 3); Reinke crystals (Leydig cell tumor, precocious puberty or gynecomastia); fried-egg cells with lymphocytic infiltrate (seminoma); "chocolate cyst"-like is ovarian, not testicular.
• Varicocele: bag of worms that decompresses when supine. One that does not decompress, or a new right-sided varicocele, mandates abdominal imaging for retroperitoneal malignancy.
• Epididymitis in a young sexually active man: empiric ceftriaxone 500 mg IM once plus doxycycline per CDC guidance; add or substitute a fluoroquinolone when enteric organisms or insertive anal intercourse are implicated.
• Screening: the USPSTF recommends against routine testicular cancer screening (self- or clinician exam) in asymptomatic adolescents and men — a grade D recommendation examiners love to invert.
• Transillumination separates hydrocele/spermatocele from a solid tumor, but any firm intratesticular mass in a young man is cancer until proven otherwise.