ABSTRACT
The majority of solid neoplasms that develop within the testis are malignant and 95% of these are germ cell tumors (GCT). These GCTs are classified by their histological appearance into seminomas (60-70% incidence, age range 20-40 years) and non-seminomatous germ cell tumors (NSGCTs), which in the UK are often referred to as teratomas (incidence 30-40%, age range 15-30 years). Tumors with mixed elements (15-30%) are managed as for NSGCTs. This histological classification correlates well with the natural history of the tumor types and also their response rates to modern treatment modalities. Seminomas are radiosensitive but both seminomas and NSGCTs respond well to cisplatin-based chemotherapy regimens with 5-year survival rates of 90% for all GCTs and > 95% for all seminomas. Prognosis is most favorable in low volume disease with a 99% 5-year survival rate for all stage I tumors but less favorable rates (∼60%) for the rarer cases of advanced tumors with visceral metastases. Although testicular tumors are rare with an incidence of about 3/100 000 in the UK and account for only 1% of all male cancers, it is the commonest solid malignancy in men in the age range 15-35 years.
