The epithelial cells may be of CO-1686 intestinal type, pancreatobiliary type or null type (similar to gastric foveolar epithelium) or morphologically unclassifiable (150). Intestinal-type IPMN often show a colloid-type pattern of invasion and are

frequently positive for CDX-2, and MUC2 but negative for MUC1, while the pancreatobiliary type is more aggressive and is negative for CDX-2, MUC2 and positive for MUC1 (150). The null type on the other hand is generally negative for MUC1, CDX-2 and MUC2 (157). Mucinous carcinomas which arise from IMPN are frequently positive for MUC1 but less often positive for MUC5AC (158). Inhibitors,research,lifescience,medical Solid-pseudopapillary neoplasm (SPN) SPN is an uncommon pancreatic tumor most often found in young women (159).

Patients present with nonspecific symptoms related to the intra-abdominal mass such as abdominal pain and early satiety. SPNs are generally large, well circumscribed Inhibitors,research,lifescience,medical tumors which can occur anywhere within the pancreas (160). Microscopically, they form dense nests of uniform eosinophilic cells surrounding delicate vasculature resembling ependymal rosettes. The tumor cells often have nuclei with grooves and clear vacuolated cytoplasm (159). Slide preparations Inhibitors,research,lifescience,medical from material obtained by fine-needle aspirate biopsy show a distinct “Chinese character-like” appearance due to the branching capillaries are surrounded by small uniform tumor cell and show prominent nuclear grooves and/or inclusions in the tumor cells and background of metachromatic myxoid material

(161). The tumor cells are positive for alpha-1-antitrypsin, vimentin, NSE, ER-β, PR, CK8/18, CD10, CD56 and synaptophysin (153,162,163). These tumors have a mutation of the β-catenin gene and show a diffuse cytoplasmic and nuclear positivity in virtually all cases by immunohistochemistry Inhibitors,research,lifescience,medical (164). Because the β-catenin complex activates transcription Inhibitors,research,lifescience,medical of cyclin D1, nuclear cyclin D1 immunoreactivity is detected in up to 75% of SPNs (165). SPNs have also been found to show a loss of cell-cell adhesion molecule and thus are negative for E-cadherin (166). Serous cystic neoplasms (SCN) SCN are neoplasms else composed of glycogen-rich, ductular-like epithelial cells. Most SCNs are benign while others may be precursors to invasive cancer. Correlation with the patient’s age, gender, relationship between cysts and larger pancreatic ducts, cysts contents (serous fluid, mucin or necrotic debris), lining cell and nature of the stroma are all required in evaluation. Serous cystadenomas are more common in females and often present with nonspecific symptoms such as pain, nausea, weight loss. These tumors are well-circumscribed masses which on sectioning shows innumerable small cysts with a “honeycomb” appearance and often a central scar (167). The cells have a central round to oval nuclei, inconspicuous nucleoli and clear cytoplasm and are positive on periodic acid-Schiff (PAS) stain due to the abundant intracytoplasmic glycogen.