ABSTRACT
CONTEXT: Pseudotumoral chronic pancreatitis can be difficult to differentiate from pancreatic carcinoma. OBJECTIVE: To evaluate the role of endoscopic ultrasound and fine needle aspiration in differentiating between inflammatory masses and malignancies in chronic pancreatitis. DESIGN: Retrospective study. SETTING: Tertiary care endoscopy unit. PATIENTS AND INTERVENTIONS: Between February 1997 and December 2006, 69 pancreatic head masses from patients with alcoholic chronic pancreatitis underwent EUS-FNA using a linear echoendoscope and 22-gauge needles. Final diagnoses were obtained from surgery or clinical follow-up. The patients were subdivided into two groups: pseudotumoral chronic pancreatitis and pancreatic cancer. RESULTS: Pseudotumoral masses and adenocarcinoma were found in 58 and 11 patients, respectively. The size of the lesions and the clinical presentation were similar in both groups, but the cancer patients were older than the patients with pseudotumoral masses (P=0.020). Fourteen of the 58 (24.1%) pseudotumoral masses were misdiagnosed as cancers, and 4 of the 11 (36.4%) cancers were erroneously diagnosed as pseudotumoral masses when evaluated by EUS alone. EUS-FNA confirmed the final diagnosis in 66 of the 69 (95.7%) cases. Cytopathology correctly classified 8 of the 11 (72.7%) malignancies and all benign cases. Three of the 11 (27.3%) cancers were misdiagnosed as pseudotumoral masses, and no pseudotumoral mass was diagnosed as a cancer. In two cases, the specimens were inadequate for cytopathological assessment. The sensitivity, specificity, positive and negative predictive values, and the diagnostic accuracy of EUS-FNA were 72.7%, 100%, 100%, 95.1% and 95.7%, respectively. CONCLUSIONS: The diagnostic accuracy of endoscopic ultrasound alone for differentiating between pseudotumoral masses and pancreatic cancer arising from chronic pancreatitis is unsatisfactory. Fine needle aspiration of these tumors significantly improves diagnostic capability.
