Seminoma is a type of testicular cancer that originates in the germ cells, which are responsible for producing sperm. It is one of the most common forms of testicular cancer, particularly affecting young men between the ages of 15 and 35. Seminomas are generally slow-growing and can often be treated successfully, especially when detected early. There are two main types of seminomas: classic seminomas and spermatocytic seminomas. Classic seminomas are more common and tend to respond well to treatments like surgery, radiation, and chemotherapy. Spermatocytic seminomas are rarer and usually occur in older men, with a better prognosis. Early diagnosis is crucial for effective treatment.