Figure 2.

Epithelial cells were polygonal, with thin and transparent cytoplasm and center located round nuclear. After 3-4 days culture, cells developed the appearance of decidual cell-like transformation with larger size. The cytoplasms were large and bright and the size of nucleus significantly increased. Cells were arranged in spiral-like or dough pattern with gradually outward derivative, and showing filamentous connection (A). Stromal cells had fibroblast morphology, spindle-shaped, abundant cytoplasm, oval-shaped nuclear. They were easy to passage. After long-term culture, these cells were arranged in parallel bundles, with dense piles of regional aggregation (B).