1. The tumor appears as a fairly well circumscribed, pale, fleshy, homogeneous mass Seminoma of the testis

2. Large cells with distinct cell borders, clear cytoplasm, rounded nuclei, prominent nucleoli, and a sparse lymphocytic infiltrate. Seminoma of the testis

3. There is diffuse proliferation of tumor cells with characteristic spireme-type chromatin pattern Spermatocytic seminoma

4. Embryonal ca testis This shows solid nodular invasive (ill-defined) cut surface with numerous areas of necrosis and hemorrhage.

5. Sheets of undifferentiated cells as well as primitive glandular differentiation. The nuclei are large and hyperchromatic with prominent nuclei Embryonal carcinoma

6. A, Embryonal carcinoma displaying a papillary pattern of growth (hematoxylin-eosin, original magnification ×100). B, Embryonal carcinoma cells characterized by marked anaplasia and abnormal mitotic figures (hematoxylin-eosin, original magnification ×400) Embryonal carcinoma

7. A, Low-power photomicrograph demonstrating areas of loosely textured, microcystic tissue and a papillary structure. B, Higher power photomicrograph demonstrating characteristic hyaline droplets within the microcystic areas of the tumor. Yolk sac (endodermal sinus) tumor

8. A, Yolk sac tumor with a reticular, microcystic pattern characterized by thin anastomosing cords and loose spaces (hematoxylin-eosin, original magnification ×100). B, Yolk sac tumor showing classic Schiller- Duval bodies with a central fibrovascular core surrounded by malignant cuboidal to columnar cells (hematoxylin-eosin, original magnification ×400)

9. Pleomorphism and hyaline globules in yolk sac tumor of testis. Schiller-Duval body in yolk sac tumor of testis.

10. The tumour shows cytotrophoblastic cells with central nuclei (arrowhead, upper right) and syncytiotrophoblastic cells with multiple dark nuclei embedded in eosinophilic cytoplasm (arrow, middle). Hemorrhage and necrosis are prominent. Choriocarcinoma

11. These tumors contain mature cells from endodermal, mesodermal, and ectodermal lines. Pictured here are four different fields from the same tumor containing (A) neural (ectodermal), (B) glandular (endodermal), (C) cartilaginous (mesodermal), and (D) squamous epithelial elements. Testicular teratomas

12. Mature teratoma testis gross There are multiple cystic areas, lobules of mature adipose tissue, and shiny solid nodules corresponding to well-differentiated cartilage. Large islands of cartilage are seen surrounding well-differentiated glandular structures.

13. Immature teratoma testis Microscopic appearance. Hypercellular stroma is seen growing in a concentric fashion around glandular formations.