embryonal carcinoma

Microscopic pathology

primitive or undifferentiated form
- solid aggregates of cells, epithelial-like
- medium to large sized cells, polygonal to ovoid
- ample pale eosinophilic granular cytoplasm
- ill-defined borders, often syncytial
- marked nuclear & cellular pleomorphism
- large, prominant, central, irregular vesicular/ hypochromatic nuclei
- may have giant cells or multinucleated cells
- brisk mitotic activity, atypical mitoses
more differentiated form
- in addition to solid areas, cells tend to line clefts & spaces and form papillae
- cells more epithelial in appearance
- may be suggestion of glandular formation