Yolk sac tumor accounts for more than 80% of testicular germ cell tumors in children. It displays an amazing variety of architectural patterns. The most common is microcystic pattern as shown here. Interconnecting cords and ribbons of tumor cells are surrounded by abundant myxoid stroma.
Yolk sac tumor is the commonest germ cell tumor in children. It may occure as pure form or as a part of a mixed germ cell tumor. Previously, the tumor was more often diagnosed as a clear cell carcinoma.
The tumor was also called ’mesonephroma ovarri’ due to the finding of glomeruli like structure, the Schiller-Duval body. There are actually blood vessels surrounded by primordial germ cells, a finding first noted in rat endoderm.
Architectural patterns
Schiller-Duvall bodies (Schiller-Duvall body).
- Schiller-Duvall body is a structure seen in the endodermal sinus pattern of yolk sac tumor. It consists of a central vessel surrounded by tumor cells – the whole structure being contained in a cystic space often lined by flattened tumor cells.
microcystic pattern: interconnecting cords and ribbons of tumor cells are surrounded by abundant myxoid stroma. Intracellular vacuoles and microcystic areas may sometimes resemble lipoblasts; however, the tumor cells do not contain lipid. Microcystic pattern often coexists with other architectural patterns. The tumor cells have vesicular nuclei with punctate nucleoli. Wisps of myxoid material are seen in cystic spaces. This accounts for gelatinous appearance on cut surface of the tumor.
myxomatous pattern: neoplastic stellate, spindle, or epithelioid cells in abundant myxoid stroma. Many of these cells are pluripotential and can form skeletal muscle, cartilage, and bone. Such areas should not be confused with teratoma
hepatoid pattern (20%) (hepatoid yolk sac tumor)
- sheets of polygonal cells with abundant eosinophilic cytoplasm
- hyaline globules
- bile canaculi
solid pattern
- sheets of uniform tumor cells with clear or pale pink cytoplasm
- differential diagnosis: seminoma (It lacks the fibrous septa with lymphoid infiltrate seen in seminoma. )
Localization
ovarian yolk sac tumor
vaginal yolk sac tumor
prostatic yolk sac tumor
mediastinal yolk sac tumor
Differential diagnosis (Examples)
microcystic Leydig cell tumors (10328086)
CGH (15880464)
| CGH losses | |
| 1p35-pter | |
| CGH gains | |
| 3p21-pter | 20q13 |
Case records
Case #12475: Vaginal yolk sac tumor
Web references