Mural nodules were defined as EUS-detectable, echogenic, protruding components in an ectatic (dilated) PD side branch. Branch duct IPMNs were distinguished from mucinous cystic

neoplasms of the pancreas by the presence of an obvious communication with the main PD. Surgery was deemed necessary when cytology was positive for malignancy, when mural nodules were larger than 5 mm in size or when a pancreatic mass was present. Patients with no immediate indication for surgery were followed for a minimum of 13 months (range 13-50 Akt inhibitors in clinical trials months), with repeat contrast-enhanced CT or MRI performed every 3 to 4 months. Patients who showed progressive dilation of the main and ectatic side branch pancreatic ducts, and/or development or enlargement of mural nodules or a pancreatic mass during surveillance, underwent EUS; those with confirmed mural nodules larger than 5 mm and those with pancreatic masses underwent surgery. The lavage cytology of patients identified

as having mural modules was performed by using a dual-lumen, 5F gauge coaxial catheter. Lavage selleck chemicals fluid was collected from the PD by injecting 1 mL of normal saline solution through the injection port while simultaneously aspirating 1 mL from the aspiration port: this procedure was repeated until at least 30 mL of PD lavage fluid was collected. After the procedure, the patients were kept hospitalized overnight to monitor them for signs and symptoms of post-ERCP pancreatitis, defined as new or worsened abdominal

pain associated with a 3 or more times the upper limit of normal elevation of serum amylase within 24 hours. The PD lavage fluid samples were centrifuged to create a pellet that was fixed in formaldehyde and prepared for histologic study, by both standard hematoxylin and eosin (H&E) staining and immunohistochemistry for mucins (MUC1, MUC2, MUC5AC, and MUC6). Two independent pathologists reviewed the histology: the H&E specimens were graded from classes I through V, with classes I through III being benign (normal to HSP90 adenoma with mild dysplasia), and classes IV and V being malignant (IV, neoplastic with moderate dysplasia; V, adenocarcinoma). Of 89 patients suspected of having side branch pancreatic duct IPMNs by CT and MRI, 44 (30 men, 14 women; mean age 66 years; only 27 symptomatic) were found to have mural nodules on EUS and proceeded to have ERP and PD lavage cytology. Eleven of 44 patients (25%) were positive for malignancy (class IV or V) and 33 of 44 (75%) were negative (classes I-III). Four patients reported “slight” abdominal pain post-procedure, and 5 had serum amylase levels more than 3 times the upper limit of normal. Pain resolved in the 4 symptomatic patients within 24 hours; elevated serum amylases normalized within 5 days.