1993 Volume 32 Issue 4 Pages 481-488
It was found that almost all keratotic and parakeratotic cells showed birefringence under polarized light. Other types of cells, such as endometrial stromal cells, glandular epithelial cells, adenocarcinoma cells, and non-keratinizing squamous cell carcinoma (SCC) cells, did not show birefringence under polarized light, and were therefore easily differentiated from most keratotic and parakeratotic cells. It was therefore concluded that polarizing microscopy is quite useful in identifying keratotic and parakeratotic cells. Parakeratotic cells exhibiting birefringence were classified into two subgroups, cells having a pyknotic nucleus (K, P-CELLs) and cells having a non-pyknotic nucleus (K, NP-CELLs). The nuclei of K, P-CELLs and K, NP-CELLs were smaller than those of non-keratotic cells. We consider the following three criteria to be important in the cytological diagnosis of keratinizing SCC.
1) Presence of both K, P-CELLs and K, NP-CELLs.
2) K, P-CELLs with nuclei having an area larger than 18.4, μ2.
3) K, NP-CELLs with degenerated nuclei (vacuolated aggregated chromatin pattern) having an area larger than 31.1, μ2.
In some cases, it was difficult to distinguish keratotic SCC in situ from invasive keratotic SCC or keratotic severe dysplasia from keratotic SCC in situ on the basis K, P-CELLs and K, NP-CELLs.
