Germ cell tumors are a type of cancer that originates from germ cells, which are the cells responsible for producing sperm and eggs. These tumors can develop in various parts of the body, including the testes, ovaries, and mediastinum. They can be classified into two main categories: seminomas and non-seminomas, each with different characteristics and treatment approaches. These tumors can occur in both children and adults, and their symptoms may vary depending on the tumor's location. Diagnosis typically involves imaging tests, blood tests for tumor markers, and sometimes a biopsy. Treatment often includes surgery, chemotherapy, or radiation therapy, depending on the tumor type and stage.