Hints to the diagnosis of mixed acinar-endocrine carcinoma on pancreatic fine-needle aspiration: avoiding a potential diagnostic pitfall.

Background: Mixed acinar-endocrine carcinoma (MAEC) is a rare mixed tumor of the pancreas defined by both acinar and endocrine cell differentiation.

Case: We present 2 cases of MAEC initially diagnosed as pancreatic endocrine neoplasm on fine-needle aspiration. Both patients were male, aged 51 and 75 years, and presented with 16-mm and 6-mm pancreatic masses, respectively.

Hyperplastic (serrated) polyps of the colorectum: relationship of CpG island methylator phenotype and K-ras mutation to location and histologic subtype.

We investigated the frequency of promoter region CpG island methylation (CIM) of hMLH1, MGMT, MINT1, MINT2, and p16 and K-ras mutations in a total of 79 hyperplastic (serrated) polyps (HPs) from 75 patients and correlated the molecular profiles to polyp location in the colorectum, histologic variation, and other factors. Methylation-specific PCR (MS-PCR) was used to assay CIM status. HPs that showed CIM of one or more or two or more of the genes assayed were classified as CpG island methylator phenotype (CIMP) and CIMP-high (CIMP-H), respectively.