Abstract Context: Pancreatic lesions range from benign cystic to premalignant and frankly malignant. The Papanicolaou Society of Cytopathology (PSC) was established in 2014 for pancreaticobiliary cytology, with a six-tiered system. Recently, the World Health Organization (WHO) proposed a reporting system for pancreaticobiliary cytopathology. Aims: This study aimed to apply PSC and WHO systems to pancreatic cytology samples and compare their risk assessment. Materials and Methods: The Institutional Hospital Information System was searched for all pancreatic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), transabdominal ultrasound-guided FNA (TUS-FNA), and pancreatic fluid cytology samples from January 2016 to April 2025, and cases were reassigned as per the PSC and WHO diagnostic categories by two cytopathologists. Risk of malignancy (ROM) in each diagnostic category was assessed using available histopathological, clinical, radiological, biochemical, and follow-up data. Results: Of 281 pancreatic cytology cases via EUS (64.1%) and TUS-FNA (35.9%), 197 had complete follow-up records. The ROM for the PSC categories I–VI was 58.3%, 0%, 75%, 64.7%, 100%, and 100%. For WHO system categories I–IV, VI–VII, ROM values were 66.7%, 0%, 75%, 0%, 100%, and 100%. These findings indicate that the WHO system offers more effective risk stratification. Furthermore, compared with the PSC system, the WHO system showed an increase in sensitivity (89.2% vs. 81.4%), negative predictive value (NPV; 82.7% vs. 73.9%), and accuracy (92.9% vs. 87.8%), while specificity and positive predictive value (PPV) stayed consistent at 100%. Conclusion: The WHO reporting system for pancreatic cytology offers superior risk categorization, sensitivity, NPV, and accuracy compared with the PSC system, while maintaining comparable specificity and PPV.
Gupta et al. (2026) studied this question.