yolk sac tumor
a malignant germ cell tumor of children that represents a proliferation of both yolk sac endoderm and extraembryonic mesenchyme. It is characterized by a labyrinthine glandular pattern with a papillary projection into a sinuslike space; frequently there are hyaline bodies and Schiller-Duval bodies. It produces α-fetoprotein and most often occurs in the testes, but is also seen in the ovaries and some extragonadal sites. Called also infantile embryonal carcinoma, juvenile embryonal carcinoma, yolk sac carcinoma, orchioblastoma, and endodermal sinus t.
Medical dictionary.
2011.