Background: The diagnosis of malignancy can be difficult in endocrine tumors of the pancreas. Moreover prognostically relevant factors are not available. The aim of this study was to evaluate retrospectively whether the DNA distribution pattern can differentiate between benign and malignant pancreatic endocrine tumors and secondly whether the DNA content of tumor cells gives prognostic information.
Method: Image cytometry of paraffin-embedded tumor material of 42 pancreatic endocrine tumors.
Results: In 27 benign endocrine pancreatic tumors (25 insulinomas, 2 benign nonfunctioning endocrine tumors) we could differentiate between 6 diploid, 15 hypotriploid and 6 triploid DNA histograms. In 15 malignant endocrine tumors of the pancreas we could differentiate between 1 diploid, 1 hypotriploid, 9 triploid and 4 hypertriploid tumors. All 4 patients with a hypertriploid tumor died as a consequence of their disease in contrast to only 1 patient with a diploid, hypotriploid or triploid tumor even in case of a nonradical resection.
Conclusion: With the help of quantitative DNA measurement a differentiation between malignant and benign endocrine pancreatic tumors is not possible even if the risk of malignancy increases with the DNA content. The DNA content of malignant endocrine pancreatic tumors has an influence on the long-term survival. Hypertriploid tumors have a statistically significantly worse prognosis than diploid, hypotriploid or triploid tumors.