Embryonal carcinoma

Embryonal carcinoma
Diagnosis in short
Embryonal carcinoma. H&E stain.
LM	vesicular nuclei, nuclear overlap, necrosis (common), mitoses, variable architecture (tubulopapillary, glandular, solid, embryoid bodies)
LM DDx	seminoma, mixed germ cell tumour, other carcinomas
IHC	CD30 +ve, AE1/AE3 +ve
Site	testis, ovary, mediastinum
Signs	testicular mass, pelvic mass

Embryonal carcinoma is a type of germ cell tumour. It is commonly as a component of mixed germ cell tumours.

General

• Affects young adults.
  • May be seen in women.

Gross

• Typically a testicular mass.
• May be seen in the mediastinum.

Microscopic

Features:

1. Nucleoli - key feature.
2. Vesicular nuclei (clear, empty appearing nuclei) - key feature.
3. Nuclei overlap.
4. Necrosis - common.
   • Not commonly present in seminoma.
5. Indistinct cell borders
6. Mitoses - common.
7. Variable architecture:
   • Tubulopapillary.
   • Glandular.
   • Solid.
   • Embryoid bodies - ball of cells in surrounded by empty space on three sides.

Notes:

• Cytoplasmic staining variable (eosinophilic to basophilic).

DDx:

• Yolk sac tumour.

Images

• 

  Embryonal carcinoma - very high mag. - cropped (WC/Nephron)

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  Embryonal carcinoma - high mag. (WC/Nephron)

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  Embryonal carcinoma - high mag. (WC/Nephron)

• 

  Embryonal carcinoma - intermed. mag. (WC/Nephron)

• 

  Embryonal carcinoma - low mag. (WC/Nephron)

IHC

• AE1/AE3 +ve.
• CD30 +ve.

See also

• Germ cell tumours.
• Ovarian tumours.
• Testis.