1. Seminoma is the most common malignant tumor of the testis, occurring most often in men between ages 25-55. Undescended testes are an important risk factor. 2. There are two main types of seminoma: classic seminoma, which accounts for 90% of cases, and spermatocytic seminoma, which comprises 5% of cases. 3. Classic seminoma appears as enlarged, solid testes containing white nodules separated from the testicular tissue. Under the microscope, classic seminoma cells are large with clear cytoplasm and central nuclei, and stain positive for glycogen.

1. SEMINOMA

2. • It is the commonest malignant tumor of the
testis.
• Incident age is between 25- 55 years.
• It is rare before puberty.
• Undescended testis is important causative factor

3. TYPES
• Classic seminoma
• Spermatocytic seminoma

4. CLASSIC SEMINOMA
• It constitutes about 90%
Gross appearance:
• Testis is enlarged, bulky, solid, grey white.
• Smaller nodules appear separated from testicular
tissue.
Microscopic appearance
• Tumor tissue consists of cellular tissue and fibrous
tissue

5. Tumor cell:
• The classis seminoma cell is large, round,
polygonal, with clear cytoplasm and cell border.
• These cells have glycogen and stain positive with
PAS stain.
• Nucleus is central, large, dark, hyperchromatic.
• 1-2 prominent nucleoli

6. Stroma:
• It is delicate and separates lobules of cellular
tissue.
• It contains lymphocytic infiltration.
• 20% of tumors show granulomatious reaction

7. Anaplastic seminoma:
• It constitutes 5% of all seminomas.
• Features like increased mitotic activity, nuclear
irregularity, frequent tumor giant cell do not
change the course of disease.
Clinical course:
• Classic seminoma and anaplastic seminoma
have better prognosis than other germ cell
tumor.

8. SPERMATOCYTIC SEMINOMA
• It comprises of 5% of all seminomas
• Occurs inpatients in 6th decade of life
• It is bilateral in about 10% of patients.
• It is slow growing with excellent prognosis

9. Gross appearance:
• Size is variable, usually larger than classic
seminoma.
• It is soft, yellow, gelatinous.
Cut section:
• Sometimes shows mucoid cyst.
• Hemorrhage and necrosis is rarely seen
Microscopic appearance:
• It consists of cellular elements, stromal tissue.

10. Tumor cells:
• It is of four types
• Medium sized cells: 15-18 μm, round,
abundant eosinophilic cytoplasm. These are
predominant.
• Smaller cells :6-8 μm, thin rim of eosinophilic
cytoplasm.

11. • Intermediate cells: size is intermediate. They
are very few in number.
• Giant cells: it is scattered. It has either single
large nucleus or multiple nuclei
Clinical course:
• It has got excellent prognosis and do not
contain lymphocytes