Surface Ultrastructure of the Exfoliated Trophoblastic Cell

The present study is a report regarding observation of exfoliated trophoblastic cells under light microscopy (LM) and scanning electron microscopy (SEM) by our new processing method. The cells were obtained from patients with D & C, spontaneous abortion, hydatidiform mole and destructive mole.The surface of syncytialtrophoblastic cell (ST) in normal early pregnancy has slender microvilli (mV) showing irregular distribution. In these samples adhesion to the adjacent mV and entanglement were observed.In case of abortion, there were two types of ST, with or without mV which showed a strong degeneration.Microvilli of ST observed in hydatidiform mole and destructive mole are thick, short and dense, as compared with normal early pregnancy. Syncytialtrophoblast of destructive mole tended to have thicker and denser mV than that of hydatidiform mole. It was suggested electronmicroscopically that ST appearing on the smear were syncytialsprout exfoliated from villi. Small processes which clearly differed from mV of ST were observed on the surface of multinucleated histiocyte.Cytotrophoblastic cell (CT), which had a smooth surface under SEM observation, showed hardly any difference between each disease. The cell which appeared as CT under LM had mV under SEM. It was suggested that it was probably the so-called intermediate cell which appeared in the shift from CT to ST.