Background/Objectives: Appropriate biomarkers are necessary for early diagnosis and multidisciplinary treatment of pancreatic ductal adenocarcinoma (PDAC). In recent years, the clinical utility of circulating tumor cells (CTC) as biomarkers for various can-cers has been reported; however, their detection rate in PDAC remains low, and clinical evidence is not yet established. CTC detection methods with high reliability and per-formance are essential for clarifying the importance of CTC in patients with PDAC. Methods: A total of 5 mL peripheral blood samples were collected from 38 patients newly diagnosed with PDAC and 17 healthy controls. Negatively enriched cells were immunofluorescently stained with EpCAM-phycoerythrin and cell surface vi-mentin-fluorescein isothiocyanate (CSV). Images were automatically captured using an all-in-one fluorescence microscope. Cellular regions were detected from these images, and the average luminance of the cellular regions was calculated. A total of 9086 and 1071 cell images were obtained from patients with PDAC and healthy controls, respec-tively. Results: In the EpCAM assay, a threshold that included 95% of healthy individuals was optimal for distinguishing patients with PDAC from healthy controls, with a sensi-tivity, specificity, and area under the curve of 0.74, 0.76, and 0.84, respectively. At this threshold, the CTC-positivity rate in patients with PDAC was 76.3%. Conversely, the CSV assay failed to demonstrate a valid threshold to distinguish patients with PDAC from healthy controls. No significant differences were found between CTC and clini-copathological features among patients with PDAC. Conclusions: The method using high-resolution image scanning has the potential to identify CTC with greater objectiv-ity by quantifying cell luminance values.

Objectives: Whether lymph node dissection is necessary for pancreatic neuroendocrine neoplasms (pan-NEN) smaller than 20 mm in diameter remains controversial. We aimed to investigate the usefulness of apparent diffusion coefficient (ADC) values on diffusion-weighted magnetic resonance imaging (DW-MRI) in predicting lymph node metastasis (LNM) in pan-NENs. Methods: Data concerning 44 patients with pan-NENs who had undergone radical pancreatectomy in our department between January 2008 and December 2023 were retrospectively reviewed. ADC values of the tumor area on DW-MRI were measured and analyzed in relation to clinicopathologic factors. Results: Thirty-three patients had pan-NENs smaller than 20 mm in diameter. Six patients with LNM showed significantly lower ADC values than those without ( P = 0.0105). Of the patients with pan-NENs smaller than 20 mm in diameter, 4 patients with LNM had significantly lower ADC values ( P = 0.0010). Regarding vascular invasion, the patient group positive for lymphatic, venous, and neural invasion had significantly lower ADC values than those in the negative group ( P = 0.018, 0.036, and 0.033, respectively). Conclusion: In cases of pan-NENs smaller than 20 mm in diameter, low ADC values may predict LNM and vascular invasion.