Testicular cancer accounts for about 1 % of all cancers in men. Malignant testicular tumors are divided into two main groups: germ cell tumors and non-germ cell tumors. Germ cell tumors are subdivided into two groups: seminomas and nonseminomatous germ cell tumors such as embryonal carcinoma, yolk sac tumor, teratoma, choriocarcinoma, and mixed germ cell tumor. Non-germ cell tumors consist of Leydig cell tumor, Sertoli cell tumor, granulosa cell tumors, fibroma–thecoma tumors, mixed sex cord–stromal tumors, lymphoma, leukemia, and metastases. Radiological evaluation of testicular tumors is mainly based on ultrasound findings. The main role of ultrasound examination is to distinguish intratesticular from extratesticular lesions, because the majority of the extratesticular masses are benign and intratesticular masses are more likely to be malignant. MRI has an advantage over ultrasound in distinguishing an intratesticular hematoma from a testicular neoplasm.
