Background—Circulating epithelioid cells (CECs), also known as circulating tumor/cancer/
epithelial/non-hematologic cells, are a prognostic factor in various malignancies that can be
isolated via various protocols. We analyzed the cytomorphologic characteristics of CECs isolated
by size in a cohort of patients with benign and malignant pancreatic diseases to determine if
cytomorphological features could predict CEC origin.
Methods—Blood samples were collected from 9 healthy controls and 171 patients with
pancreatic disease presenting for surgical evaluation prior to treatment. Blood was processed with
the ScreenCell size-based filtration device. Evaluable CECs were analyzed in a blinded fashion for
cytomorphologic characteristics including cellularity, nucleoli, nuclear size/irregularity/variability/
hyperchromasia, and nuclear-cytoplasmic ratio. Statistical differences between variables were
analyzed via Fisher's exact test.
Results—No CECs were identified in normal healthy controls (n=9). Of the 115 patients with
CECs (positive or suspicious), 25 had non-malignant disease and 90 had malignancy. There were
no significant differences in any of the cytologic criteria between groups divided by benign versus
malignant, neoplastic versus non-neoplastic, or pancreatic ductal adenocarcinoma versus
neuroendocrine tumor.
Conclusions—CECs were seen in patients with malignant and non-malignant pancreatic
disease, but not in healthy controls. There were no morphologic differences between cells from
different pancreatic diseases. This suggests that numerous conditions may be associated with
CECs in the circulation and that care must be taken not to over-interpret cells identified by
cytomorphology as indicative of circulating tumor cells of pancreatic cancer. Additional studies
are required to determine the origin and clinical significance of these cells.
