Abstract
The presence of intermediate trophoblastic cells in uterine curettings is considered a reliable indicator of intrauterine implantation. However, this highly invasive trophoblast is difficult to recognize with conventional staining. Nevertheless, cytokeratin antibodies are reliable markers of this cell type. A previous study has described multiple deep clefts in the nuclei of these cells. The present study was performed to identify the specific histologic feature of intermediate trophoblasts and to test the accuracy of this finding in the diagnosis of intrauterine pregnancy in curettings lacking chorionic villi. The author reviewed 170 abortion specimens. The specimens were divided into two main groups: (1) intrauterine gestations with villi and (2) intrauterine gestation without villi. Each group was further divided into three subgroups on the basis of the presence or absence of large cells with multiclefted nuclei (MCN). In-termediate trophoblasts were identified in 97% of the cases in group I; 63% of these cells possessed MCN. On the other hand, Intermediate trophoblasts were identified in 59% of specimens of group II; 31% of those showed MCN. The nature of these cells was further confirmed by immunohistochemical staining. The author concludes that intermediate trophoblastic cells can reliably be identified by morphologic assessment of the routine H & E sections.