A retrospective review evaluated cytological features of pancreatic cancer using liquid-based cytology (LBC) from 254 fine-needle aspiration (FNA) samples obtained at a single institution between 2016 and 2023. The study examined cytomorphologic patterns of pancreatic ductal adenocarcinoma and assessed the diagnostic utility of cell block preparation. LBC findings associated with malignancy included: necrotic background, intermediate to high cellularity, mixed architecture, nuclear-to-cytoplasmic ratio greater than 0.8, anisonucleosis exceeding 4:1, irregular and thickened nuclear membranes, multinucleated tumor cells, hyperchromatic nuclei, coarse to clumped chromatin, and prominent single nucleoli. These findings, published in The Journal of Pathology and Translational Medicine, were observed at significantly higher frequencies in malignant cases compared with benign or atypical lesions.
Among patients with histologically confirmed pancreatic ductal adenocarcinoma, those receiving palliative therapy demonstrated necrotic backgrounds more frequently than those who underwent surgical resection, suggesting an association with advanced disease. In LBC preparations, necrosis was identified more commonly in malignant than benign samples. The presence of necrotic debris, in combination with other cytological features, was evaluated as a potential indicator of unresectability, although confounding factors such as neoadjuvant therapy and sample size were noted.
Cell blocks were successfully produced from 230 of 254 fine-needle aspiration samples (91 percent). Of these, 225 were evaluable. In 16 samples, tumor cells not visualized on LBC slides were identified only on cell block sections. In 13 samples, differential diagnoses were supported by immunohistochemical stains, special stains, or molecular tests performed on cell blocks. These included diagnoses of neuroendocrine tumors, lymphomas, metastatic carcinomas, and Mycobacterium tuberculosis infection. Molecular testing was performed in three cases, including KRAS mutation analysis and in situ hybridization for Epstein-Barr virus and Mycobacterium species.
LBC preparations showed reduced background interference from blood and mucin, consistent with previous reports. While cell blocks provided material for ancillary testing and architectural context, limitations included potential variability in staining and artifact-related exaggeration of cytologic atypia. Findings were based on a single-institution cohort, and interpretation bias could not be excluded due to the retrospective design.
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