The Papanicoloau Society of Cytopathology Guidelines for the Classification of Pancreaticobiliary Lesions

The cytologic diagnosis and classification of pancreaticobiliary lesions are complex in that any classification scheme must not only address the separation of benign and malignant lesions but also include intermediate categories reflecting the cytopathologist’s security as to whether a malignancy is present. In addition, the classification system must perform equally well for brushing and endoscopic ultrasound–guided fine-needle aspiration specimens and address the diagnosis of both solid and cystic lesions. It should also provide appropriate categories for premalignant lesions. The Papanicolaou Society of Cytopathology guidelines for pancreaticobiliary disease include a 6-category scheme addressing these issues. Categories are nondiagnostic, benign, atypical, neoplastic, suspicious for malignancy, and malignant. Several of these categories are subdivided to more completely characterize lesions, assess malignancy risk, and guide follow-up.