• Clinical science

Testicular tumors


Testicular tumors most commonly occur in men between 20 and 35 years of age, and are the most common solid malignancy in this group. Most often, patients present with a painless nodule or swelling of the testis. Diagnosis is made primarily based on palpation and findings on testicular ultrasound. Diagnostic staging further includes an abdominopelvic and chest CT, determination of serologic tumor markers (AFP, HCG, LDH), and radical inguinal orchiectomy of the affected side to confirm the diagnosis and to evaluate the histopathology (seminoma vs. nonseminoma). The necessity and choice of adjuvant treatment depends on tumor pathology, staging, and prognosis. Treatment options include active surveillance, retroperitoneal radiotherapy, retroperitoneal lymph node dissection, and platinum-based chemotherapy. The overall prognosis of testicular tumors is excellent; patients can often be cured even in advanced, metastatic stages.


  • Most common solid malignant tumor in young men in the US
  • Peak incidence: 20–35 years; (nonseminomas peak in the third decade, seminomas in the fourth decade of life)


Epidemiological data refers to the US, unless otherwise specified.




Testicular tumors are classified according to pathology.

Overview of testicular tumors
Frequency AFP HCG Characteristics Pathology

Germ cell tumors of the testis (95%)
Seminoma tumor

∼ 40%

- -/↑
  • Good radiosensitivity; slow growth, late metastases, and better overall prognosis compared to nonseminomas
  • Uniform white cut section
Nonseminoma tumors Embryonal carcinoma ∼ 25%



  • Grey-white regressive changes with hemorrhage, necrosis, and cysts
Teratoma ∼ 25% - -
  • Rare in adults, but common in children
  • Typically benign but may be malignant in adults (teratocarcinoma)
  • Composed of tissue from different germinal layers.
  • May be immature or may contain fully differentiated elements muscle, cartilage, bone, teeth) in mature teratomas
Testicular choriocarcinoma ∼ 5% - ↑↑
Yolk sac tumor ∼ 5% -
  • Most common prepubertal testicular tumor
  • Yellow cut surface, glomeruloid structures (Schiller-Duval bodies)
Mixed germ cell tumors Most common overall -/↑ -/↑
  • Heterogeneous cut surface with solid areas, hemorrhage, and necrosis
Non germ cell tumors of the testis (5%) Leydig cell tumors ∼ 2% - -
  • Definition: rare tumors which arise from the hormone producing stromal cells of the testes.
  • Epidemiology: usually develop after the age of 4
  • Pathophysiology: produces ↑↑ amounts of testosterone and a small amount of estrogen, progesterone, and corticosteroidstestosterone excess causes precocious puberty in males (and masculinization in females)
  • Clinical features
    • Androgen excess features, like prominent external genitalia, pubic hair growth, accelerated skeletal and muscle development, and mature masculine voice
    • Occassionally, estrogen excess features, like gynecomastia, breast tenderness, and gonadogenital underdevelopment.
    • Malignant transformation is very rare.
  • Reinke crystals (eosinophilic cytoplasmic inclusions)
Sertoli cell tumors < 1% - -
Secondary testicular tumors Lymphoma Most common testicular tumor in men > 60 years of age - -
  • Usually diffuse large B-cell lymphomas

HCG is always elevated in cases of choriocarcinoma and sometimes in seminoma. AFP is always elevated in yolk sac tumors. In mixed germ cell tumors, both AFP and HCG may be elevated.

Testicular tumors metastasize early via the lymphatic system into the retroperitoneum (drain to the para-aortic lymph nodes first), with the exception of early hematogenously metastasizing choriocarcinomas.


Clinical features

Until proven otherwise, a firm nodule on the testis should be considered cancer!

Subtypes and variants

Extragonadal germ cell tumors



Staging of testicular tumors is based on the American Joint Committee on Cancer (AJCC) groups, which combines TNM stage and serum tumor marker levels.

Simplified AJCC classification
Stage I Limited to the testicles without lymph node involvement
Stage II

Retroperitoneal (beneath the diaphragm) lymph node involvement

Stage III

Distant metastases or nonregional lymph node involvement, or retroperitoneal lymph node involvement with moderately to highly elevated tumor markers



Suspicion of testicular tumor is usually established based on the clinical findings and ultrasound (to localize the tumor).

If a testicular tumor is suspected, the testis should be removed and sent to pathology. Transscrotal biopsy should not be conducted because of the risk of tumor seeding!


Differential diagnoses

Differential diagnosis of painless testicular swelling
Clinical features Ultrasound
Testicular tumor
  • Usually painless mass (however, may feel dull ache or "heavy" sensation in the testicle)
  • Palpation of solid mass
  • Negative transillumination test
  • Solid mass with variable echogenicity
Hydrocele testis
  • Fluctuant swelling of the scrotum
  • Palpation of an elastic soft swelling
  • Positive transillumination test
  • Hypoechoic mass around the testis
Varicocele testis
  • Usually painless ; swelling may be reduced when supine
  • Visible or palpable strands and “bag of worms” sensation
  • Negative transillumination test
  • Dilated hypoechoic pampiniform vessels
Spermatocele testis
  • Fluctuant swelling of the upper testicular pole
  • Positive transillumination test

Hypoechoic dilation of epididymal duct or rete testis

Scrotal hernia
  • Visible groin protrusion
  • Bowel sounds on auscultation over scrotum
  • Herniated bowels


The differential diagnoses listed here are not exhaustive.



Adjuvant radiotherapy and chemotherapy

Staging according to the classification Seminoma Nonseminoma
Stage I

Stage II

Stage III
  • Chemotherapy (depending on prognosis): BEP1 or EP2 followed by evaluation of any residual disease that may require resection
1BEP = chemotherapy with bleomycin, etoposide, and cisplatin, 2EP = chemotherapy with etoposide, cisplatin, 3RPLND= retroperitoneal lymph node dissection



  • The overall prognosis of testicular tumors is excellent, with a high cure rate and 5-year survival rates of > 95%.
  • Even in advanced, metastatic stages, testicular tumors are often curable.

Testicular tumors, particularly seminomas, are one of the few cancers that can be cured even in very advanced stages with adequate treatment. Patients with nonseminomas have a significantly poorer prognosis but still an excellent overall survival rate!