There are 5 stages during the development of embryo, including the stage of 2-celled proembryo, multicellular proembryo, globular proembryo, pyriform proembryo, differential embryo and mature embryo.
Granulocytic sarcoma (GS), also known as extramedullary myeloblastoma or chloroma is an unusual manifestation and represent soft tissue masses composed of immature cells of the granulocytic series.
The midgut gland cell differentiation occurs at Z2, There are 4 types of cells, i. e., embryonic cell (E-cell), fibrillar cell (F-cell), blister cell (B-cell) and resorptive cell(R-cell).