Phenotypical characteristics of undifferentiated carcinoma of the pancreas: a comparison with pancreatic ductal adenocarcinoma and relevance of E-cadherin, alpha catenin and beta catenin expression.

The characteristics of undifferentiated (anaplastic) carcinoma (UC) of the pancreas were analysed and compared with those of poorly differentiated adenocarcinoma (PA). Eight cases of UC of the pancreas were evaluated by clinicopathological and immunohistochemical methods and compared with 20 cases of PA. Large size of the tumor, local invasion and lymph node metastasis were frequently seen in UC, leading to a significantly worse prognosis compared to that of PA (p=0.022). Immunohistochemically, E-cadherin expression was completely lost in 7/8 UC cases, whereas half the PA cases revealed a strong reactivity for E-cadherin. alpha- and beta-catenin expressions tended to be impaired in UC compared with PA. The results suggest that the altered expression of adhesion molecules is correlated with dedifferentiated change and is contributory to its aggressive biological behaviour.