All of the following clinicopathologic features are seen more often in seminomas as compared to nonseminomatous germ cell tumors of the testis except

While hCG concentration may be inceased in patients with either nonseminoma or seminoma histology, the AFP concentration is increased only in patietns with nonseminoma." - Harrison Seminomas represent about 50% of all Germ cell tumors of testis. Median age is 4th decade (Nonseminomas are most frequent in the 3rd decade). Seminomas follow a more indolent course. Most seminomas (70%) present with stage I disease (disease limited to testis), about 20% with stage II disease (with retroperitoneal metastases), and 10% with stage III disease (spread beyond retroperitoneum) Seminomas as well as non-seminomas typically metastasize through lymphatics (except Choriocarcinoma which demonstrates early hematogenous spread) Seminomas are one of the most radiosensitive tumors (Non seminomas are insensitive to radiation). ref : Bailey & Love 25/e p1384