Abstract
Objectives : The present study was aimed at clarifying the cytological features of epithelial-mesenchymal transition (EMT) cells in effusion cytology in cases of pancreatic cancer.
Methods : We examined the features of EMT cells in the effusion cytology specimens of 33 cases of pancreatic cancer. We analyzed the immunoreactivities of the cells for EMT-related markers, such as E-cadherin, vimentin, and Zinc finger E-box binding homeobox 1 (ZEB1), and also the cytological features of the vimentin- and ZEB1-positive EMT cells in the effusion cytology specimens.
Results : Pancreatic cancer cells identified in effusion cytology were classified as the clustered type (36.3%), isolated (15.2%) or mixed type (48.5%). The EMT cells showed positive staining for E-cadherin, vimentin, and ZEB1 30 (90.9%), 6 (18.2%), and 4 (12.1%) of the effusion cytology specimens, respectively. Immunoreactivity for the EMT-related markers of E-cadherin and vimentin, but not for that of ZEB1, was closely related to the types of cells. In four of the specimens (12.1%) examined, including 2 with mixed-type cells and 2 with isolated-type cells, the EMT cells showed positive immunoreactivity for both vimentin and ZEB1. The EMT cells in the effusion cytology specimens occurred mainly as isolated, round, and or loosely aggregated clusters of cells.
Conclusions : The EMT cells in the effusion cytology specimens appeared as isolated or loosely clustered cells, and did not exhibit fibroblast-like morphological change. Therefore, it is of importance to understand the diversity of EMT cells in effusion cytology specimens.
