Histologic Changes of Seminoma

Cells are rounded with clear (glycogen-rich) cytoplasm and sharp cell borders. Nests of tumor are surrounded by narrow bands of fibrous tissue that are usually infiltrated with lymphocytes and plasma cells ± granulomas. Mitoses vary in number.

Note the clear tumor cells and the lymphoid cells in the fibrous tissue.

Nuclei are central and have clumped chromatin and a prominent nucleolus. The clear cytoplasm gives a "fried egg" appearance.

Tumors with small areas of cellular pleomorphism (early carcinomatous transformation), trophoblastic giant cells, or yolk sac features (Schiller-Duval bodies) should be so designated in the diagnosis. They are treated as seminoma. Tumors with larger discrete foci of nonseminomatous germ cell tumor (NSGCT (combined patterns)) are treated as NSGCT.

Discussion

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