SEMINOMA.pptx ...........................

It's a carcinoma

1. SEMINOMA

2. Classification 1. Classical or typical 2. Anaplastic 3. Spermatocytic seminoma

3. Classical Seminoma Seminomas are the most common type of germ cell tumor (~50 % of germ cell tumors). Age group: Peak incidence is during third decade (between 30 and 40 years) and almost never found in infants or prepubertal children. Female counterpart occurs in the ovary is known as dysgerminoma . Genetic alterations : – Seminomas contain an isochromosome 12p (gain of additional fragment short arm of chromosome 12), and express OCT3/4 and NANOG. Mutations of KIT (oncogene) in about 25% of tumors. KIT amplification and overexpression may also occur without genetic defects. Origin : Classic seminoma arises from undifferentiated germ cells.

4. Gross Seminomas are bulky , solid , rubbery-firm , and bosselated tumors. Size : It varies from 2 to 6 cm and testis is enlarged , sometimes up to ten times of the normal testis. Cut surface: Tumor is homogeneous , gray-white or grayish yellow, and lobulated . Tumor is sharply demarcated from normal testis, which may be compressed, and atrophic. Usually , the tunica albuginea is not penetrated . Areas of necrosis or hemorrhage are usually not seen.

5. Microscopy : Poorly demarcated lobules of uniform seminoma cells. Delicate fibrous septa Septa infiltrated with lymphocytes and plasma cells.

6. Seminoma appears microscopically similar to dysgerminoma of ovary. 1 . Pattern: Tumor is composed of sheets or nests or cords of uniform population of seminoma cells. 2 . Classic seminoma (tumor) cells: They have following features: Uniform single population of cells that resemble spermatogonia . Cells are large, round to polyhedral and have a distinct cell membrane. Cytoplasm : May appear pale and eosinophilic or clear (watery). It contains varying amounts of glycogen and some lipid . Nucleus : Large, central vesicular nucleus with one or two prominent nucleoli . Mitoses vary in number

7. 3. Stroma: Seminoma cells divided into poorly demarcated lobules by delicate fibrous septa. Fibrous septa are infiltrated with moderate amount of lymphocytes and plasma cells. 4. Immunohistochemistry: Seminoma cells are diffusely positive for: KIT . OCT4 and placental alkaline phosphatase (PLAP) on the plasma membrane.

8. Spread Local spread: I nvasion of the testicular parenchyma. Spread into rete testis. Invasion of the epididymis . 2 . Lymphatic spread : To abdominal lymph nodes . Prognosis of Seminoma Extremely radiosensitive. Remain localized to the testis for long time Metastases mainly involve lymph nodes . Hematogenous spread occurs late. Best prognosis

9. Anaplastic Seminoma Anaplastic seminoma is cellular and shows nuclear pleomorphism with more frequent tumor giant cells and many mitotic figures. Not associated with worse prognosis than classic seminoma.

10. Spermatocytic Seminoma Spermatocytic seminoma is a distinctive tumor of testis both clinically and morphologically. It is rare tumor (~1 to 2% of all testicular germ cell tumors). Origin : Spermatocytic seminoma originates from germ cells undergoing spermatogenesis. Represent more differentiated type of germ cell tumor. Age : Usually above 65 years of age.

11. MORPHOLOGY Gross Soft and pale gray . Cut surface may show mucoid cysts. Microscopy Three types of cells Small lymphocyte-like 2 . Intermediate 3 . Giant.

12. Smaller lymphocyte-like cells: These cells have a thin rim of eosinophilic cytoplasm. They resemble secondary spermatocytes. Medium-sized intermediate cells: They show eosinophilic cytoplasm and round nucleus and they are the most numerous cells seen. Large cells: Scattered giant cells, either uninucleate or multinucleate may be seen. The chromatin in some tumor cells is filamentous in appearance, similar to that seen in the meiotic phase of non-neoplastic spermatocytes ( spireme chromatin).

13. Prognosis Slow-growing tumor: It does not produce metastases. Prognosis : Excellent.