Germ Cell Tumor: Types, Symptoms, Diagnosis and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Germ cell tumors (GCTs) arise from primordial germ cells and are classified as gonadal (testicular or ovarian) or extragonadal (mediastinal, retroperitoneal, pineal, sacrococcygeal). Testicular GCTs are the most common malignancy in males aged 15–35 years, with an annual incidence of approximately 10 per 100,000 males in Western countries. They are divided into seminomas (40–50%) and non-seminomatous germ cell tumors (NSGCTs, 50–60%), which include embryonal carcinoma, yolk sac tumor, choriocarcinoma, and teratoma. Ovarian GCTs — predominantly dysgerminoma (the ovarian equivalent of seminoma), immature teratoma, and yolk sac tumors — account for ~3–5% of ovarian malignancies and primarily affect women under 30. Extragonadal GCTs arise in the mediastinum (most common extra-gonadal site), retroperitoneum, and CNS. GCTs are among the most curable solid tumors: overall 5-year survival exceeds 95% due to exquisite cisplatin sensitivity, even in metastatic disease.

Cryptorchidism (undescended testis) is the strongest risk factor for testicular GCT, increasing risk 3- to 5-fold even after orchidopexy. Risk persists regardless of whether orchidopexy is performed early or late. A contralateral testicular GCT increases risk in the opposite testis 25-fold. Family history (father or brother) elevates risk 4–8 fold, implicating shared genetic susceptibility — GWAS studies have identified susceptibility loci at KITLG, SPRY4, BAK1, and DMRT1. Testicular dysgenesis syndrome — integrating cryptorchidism, hypospadias, reduced semen quality, and testicular GCT — is hypothesized to result from fetal endocrine disruption during gonadal development. Klinefelter syndrome (47,XXY) is associated with mediastinal GCTs (relative risk ~50×). HIV infection increases GCT risk 2-fold. Caucasian males have a substantially higher incidence than African or Asian males, suggesting a genetic or environmental interaction.

Testicular GCTs typically present as a painless, firm testicular swelling or mass — the classic presentation. Dull ache or heaviness in the testis or scrotum is reported by ~40% of patients. Acute testicular pain mimicking epididymitis occurs in ~10% of cases (due to hemorrhage or infarction within the tumor) and frequently leads to diagnostic delays. Gynecomastia — due to hCG secretion by choriocarcinoma elements — is present in ~5% of patients. Advanced retroperitoneal lymph node metastases cause back or flank pain. Mediastinal GCTs present with chest pain, cough, dyspnea, or superior vena cava syndrome. CNS metastases — most common in choriocarcinoma — may cause headache, focal neurological deficits, or seizures. Hemoptysis from pulmonary metastases of choriocarcinoma-containing NSGCTs is an emergency. Significant B symptoms (fever, night sweats, weight loss) suggest bulky metastatic disease.

Scrotal ultrasound is the initial investigation, demonstrating intratesticular hypoechoic mass with near-100% sensitivity. Serum tumor markers — AFP (alpha-fetoprotein), hCG (human chorionic gonadotropin), and LDH — must be drawn before orchiectomy; marker kinetics post-orchiectomy are critical for staging and treatment planning. Seminomas may elevate hCG (15–20%) but never AFP; AFP elevation in an apparent seminoma indicates NSGCT component requiring NSGCT treatment protocols. Radical inguinal orchiectomy provides histological diagnosis and is also definitive local therapy; trans-scrotal biopsy is contraindicated due to risk of regional lymph node drainage alteration. CT chest/abdomen/pelvis delineates retroperitoneal and mediastinal lymph node involvement. PET-CT is valuable in seminoma to assess post-chemotherapy residual masses. Staging follows the AJCC 8th edition TNM-S system incorporating tumor markers (S0–S3). IGCCCG risk classification (good/intermediate/poor) guides intensity of systemic therapy.

Radical inguinal orchiectomy is the universal first step. Stage I seminoma is managed by surveillance (80–85% cure, sparing 70–80% of patients from further therapy), one course of carboplatin AUC7, or adjuvant radiotherapy to the para-aortic nodes. Stage I NSGCT with low-risk features (no lymphovascular invasion, no embryonal carcinoma predominance) is managed by surveillance; high-risk features prompt adjuvant BEP chemotherapy (1 cycle) or retroperitoneal lymph node dissection (RPLND). Metastatic disease (Stage IIA–IIIC) is treated with BEP chemotherapy (bleomycin, etoposide, cisplatin): 3 cycles for good-risk and 4 cycles for intermediate/poor-risk per IGCCCG classification, achieving cure rates of 90%, 75%, and 50%, respectively. Post-chemotherapy RPLND is performed for residual retroperitoneal masses >1 cm in NSGCT. High-dose chemotherapy with autologous stem-cell transplant is reserved for relapsed or refractory disease. Salvage regimens include TIP (paclitaxel, ifosfamide, cisplatin) and VeIP (vinblastine, ifosfamide, cisplatin).

Germ cell tumors are among the most curable solid tumors, with overall 5-year survival exceeding 95% for all stages combined. Stage I seminoma has cure rates of 99% with surveillance or adjuvant treatment. Stage I NSGCT with surveillance achieves 99% long-term survival. Metastatic disease (Stage IIA–IIIC) is stratified by the IGCCCG risk classification: good-risk patients achieve 5-year survival of 90–95% with 3 cycles of BEP; intermediate-risk patients achieve 75–80%; poor-risk patients achieve approximately 50%. Long-term survival for those achieving complete remission after BEP is excellent, with very low late-relapse rates. Relapsed GCT treated with salvage TIP or high-dose chemotherapy with ASCT achieves long-term remission in 30–40% of cases. Key prognostic factors include histological type (seminoma vs NSGCT), IGCCCG classification (serum markers AFP, hCG, LDH and metastatic site), completeness of post-chemotherapy resection, and response to first-line therapy. Long-term monitoring focuses not only on oncological follow-up but also on treatment-related late effects: cardiovascular disease, secondary malignancies, hypogonadism, and nephrotoxicity from cisplatin — all requiring life-long surveillance.

Orchidopexy for cryptorchidism before age 13 — ideally in the first year of life — reduces but does not eliminate GCT risk, and facilitates testicular self-examination. Monthly testicular self-examination (TSE) from puberty enables early detection when tumors are small and stage I, improving prognosis. Contralateral testicular biopsy to detect carcinoma in situ (CIS/GCNIS) may be offered at tertiary centers to men with strong risk factors (atrophic testis, contralateral GCT). After treatment, regular surveillance CT scans (schedule varies by stage and histology), tumor markers (AFP, hCG, LDH), and testicular self-examination are mandatory. Long-term survivors require monitoring for chemotherapy-related toxicities: cisplatin nephrotoxicity, bleomycin pulmonary toxicity, cardiovascular disease, secondary malignancies, and hypogonadism.

Any male presenting with a painless testicular mass, firmness, or asymmetric swelling should be evaluated urgently by a urologist — within 1–2 weeks at most. Do not delay evaluation assuming the mass is epididymal or inflammatory; all intratesticular masses must be considered malignant until proven otherwise by ultrasound. Acute testicular pain that partially improves does not exclude GCT — hemorrhage into a tumor can transiently reduce pain. Young males with back pain, gynecomastia, or hemoptysis should have testicular examination and tumor markers checked. Patients with prior cryptorchidism should practice monthly TSE and report any change in testicular consistency or size immediately. Women under 30 with a pelvic mass should be evaluated for ovarian GCT before assuming benign etiology.