Significance of the diagnostic categories "atypical" and "suspicious for malignancy" in the cytologic diagnosis of solid pancreatic masses.

Endoscopic ultrasound guided (EUS) fine-needle aspiration (FNA) investigation of solid pancreatic lesions has been shown to have good sensitivity and specificity. Many lesions can be definitely classified as benign or malignant but some can only be cytologically classified as "atypical" or "suspicious for malignancy". Risk for malignancy in these indeterminate categories has not been well categorized.