Clinicopathological study on the intraductal spread of small pancreatic cancer.

BACKGROUND

The aim of this study was to evaluate histopathologically the frequency, direction, and length of intraductal spread (IS) along the main pancreatic duct from the main tumor of small pancreatic cancer.

METHODS

Resected specimens from 20 cases of pTS1 (histologically 2 cm or less in diameter) pancreatic cancer (September 1983 to December 2005) were examined histopathologically. As controls, 40 resected specimens from cases of pTS2 (more than 2 cm and less than 4 cm in diameter) or larger sized pancreatic cancer (pTS2<or=) were examined in the same manner. The specimens were evaluated histopathologically as to (1) the prevalence of IS, (2) the direction and length of IS, and (3) the positive rates of transpapillary cytology of pure pancreatic juice (TPC) and biopsy of the main pancreatic duct (TPB), performed preoperatively.

RESULTS

IS was observed in 45% of pTS1 and 13% of pTS2<or= cases. In 88% of cases of pTS1, IS was observed in the direction of the ampullary side. In 40% of cases of pTS2<or=, IS toward the ampullary side was seen. The mean length of IS in pTS1 and pTS2<or= cases was 11.8 mm and 7.2 mm, respectively. Positive rates of TPC and TPB in pTS1 cases were 70% and 75%, respectively, and in pTS2<or= cases, 50% and 44%, respectively.

CONCLUSIONS

The frequency of IS was high in pTS1 cases, which suggests there is potential for improvement in establishing the histocytological diagnosis of small pancreatic cancer via the transpapillary approach with the development of adequate tools.