Background: Pancreatic lesions comprise a diverse spectrum of inflammatory, benign, premalignant, and malignant conditions. Accurate diagnosis remains challenging because of the pancreas's deep anatomical location and overlapping radiological features. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has emerged as the gold-standard minimally invasive diagnostic modality, providing high-quality cytological specimens while minimizing patient morbidity. Cytopathological evaluation of EUS-FNA samples plays a critical role in differentiating neoplastic from non-neoplastic lesions and guiding therapeutic decisions.

Objective: To evaluate the cytopathological characteristics of pancreatic lesions diagnosed by EUS-guided fine-needle aspiration and assess its diagnostic accuracy in differentiating benign and malignant lesions.

Materials and Methods: A prospective observational study was conducted on 140 patients presenting with pancreatic masses over a period of 24 months. EUS-guided FNA specimens were processed using conventional smears and cell block preparation. Cytological findings were correlated with histopathology, radiological findings, and clinical follow-up. Diagnostic parameters including sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy were calculated.

Results: Of the 140 pancreatic lesions, 96 (68.6%) were malignant, while 44 (31.4%) were benign. Pancreatic ductal adenocarcinoma was the most common malignant lesion. EUS-FNA demonstrated an overall sensitivity of 93.8%, specificity of 98.0%, and diagnostic accuracy of 95.7%. Cell block preparation and immunohistochemistry significantly improved diagnostic confidence in poorly differentiated tumors and neuroendocrine neoplasms.

Conclusion: EUS-guided FNA is a highly accurate, safe, and minimally invasive diagnostic procedure for pancreatic lesions. Combined cytomorphological evaluation and cell block preparation substantially improve diagnostic precision and facilitate ancillary molecular and immunohistochemical studies.