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.
- Risk factors
Testicular tumors are classified according to pathology.
|Overview of testicular tumors|
|Type of tumor||Frequency||AFP||HCG||Characteristics||Pathology|
|Germ cell tumors of the testis (95%)|
|Seminoma|| || || |
|Nonseminoma tumors||Embryonal carcinoma|| || || |
|Teratoma|| || || || |
|Testicular choriocarcinoma|| || || |
|Yolk sac tumor|| || || || |
|Mixed germ cell tumors|| || || || |
|Non-germ cell tumors of the testis (5%)|
|Leydig cell tumors|| || || || |
|Sertoli cell tumors|| || || || |
|Secondary testicular tumors||Lymphoma|| || || |
Testicular tumors metastasize early into the retroperitoneum via the lymphatic system (drain to the para-aortic lymph nodes first), with the exception of early hematogenous metastasizing choriocarcinomas.
- Painless testicular nodule or swelling
- Negative transillumination test
- Dull lower abdominal or scrotal discomfort is more common than acute scrotal pain.
- In metastatic disease
- In Leydig cell tumors
- Paraneoplastic hyperthyroidism: alpha subunits of HCG and TSH are identical, enabling weak stimulation of the TSH receptor in tumors with HCG overproduction. 
Until proven otherwise, a firm nodule on the testis should be considered cancer!
Subtypes and variants
Extragonadal germ cell tumors
- Definition: primary germ cell tumors that arise outside of the gonads, anywhere along the body's midline from the pineal gland to the coccyx.
- Epidemiology: 5–10% of all germ cell tumors; mostly affects young males
- Symptoms :
- Prognosis: The 5-year survival is ∼ 95% for seminomas and 45–60% for nonseminomas.
|Simplified AJCC classification|
- Laboratory tests
- CT: Because of the descended testis, the regional lymph nodes are located retroperitoneally (e.g., para-aortocaval) beneath the diaphragm.
- Histopathological confirmation: following radical inguinal orchiectomy
|Differential diagnosis of painless testicular swelling|
|Testicular tumor|| |
|Spermatocele testis|| |
|Scrotal hernia|| |
The differential diagnoses listed here are not exhaustive.
- Adjuvant therapy is based on the clinical staging group, histology (seminoma vs. nonseminoma), and the prognosis.
|Adjuvant treatment for testicular cancer|
|Staging according to the classification||Seminoma||Nonseminoma|
|Stage III|| |
|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!