Testicular yolk sac tumour

Testicular yolk sac tumours (also known as endodermal sinus tumour of the testis) is the most common childhood testicular tumour (80%), with most cases occurring before the age of two years 1. In adults, pure yolk sac tumour is extremely rare, however mixed germ cell tumour are commonly seen.


Totipotent cells, which later form extraembryonic fetal membranes, give rise to yolk sac tumours.


Perivascular structures called Schiller-Duval bodies can be found in 50% of tumours and are pathognomonic.


AFP (alpha fetoprotein) is elevated in >90% cases of yolk sac tumour. Macroscopically, the testis is replaced by a gelatinous mass. Microscopically, a positive reaction for AFP is seen in tumour cells.

Prospective radiologic characterisation of yolk sac tumour is difficult, however a heterogeneous testicular mass favours non-seminomatous germ cell tumour (NSGCT), and at age <2 years, yolk sac tumour is the favoured diagnosis.


Diffusely enlarged heterogeneous testis.


Heterogeneous testicular mass lesion with post-contrast heterogeneous enhancement, with areas of hemorrhage/necrosis 2.

If the tumour is restricted to the testis, and if the serum AFP is not elevated, orchiectomy is complete treatment, with close follow-up. If relapse occurs, chemotherapy is the treatment of choice. The lungs are most common site of recurrence.

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Article information

rID: 16197
System: Urogenital
Synonyms or Alternate Spellings:
  • Testicular endodermal sinus tumour
  • Testicular yolk sac tumours
  • Testicular yolk sac tumor
  • Testicular yolk sac tumors
  • Testicular endodermal sinus tumours
  • Testicular endodermal sinus tumor
  • Testicular endodermal sinus tumors
  • Yolk sac tumour of the testis
  • Yolk sac tumour of the testes
  • Yolk sac tumours of the testis
  • Yolk sac tumors of the testis

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