Nuclear DNA content in 27 pancreatic endocrine tumours: correlation with malignancy, survival and expression of glycoprotein hormone alpha chain.

Paraffin-embedded tissue from resection specimens of 14 functioning and 13 nonfunctioning pancreatic endocrine tumours (PET) was analysed for nuclear DNA content by image cytometry. Data on follow-up (mean 5.5 years) were available in all patients. DNA histograms with a diploid pattern were found in 13 (48%) tumours, while an aneuploid pattern was seen in the remaining 14 tumours (52%). Six (40%) of the diploid tumours and 9 (60%) of the aneuploid tumours were malignant. Survival was shorter in patients with malignant and aneuploid PET (mean 3.5 years, range 0.5-7) than in those with malignant and diploid PET (mean 5.7 years, range 3-8). Human chorionic gonadotropin-alpha was expressed in 3 of 12 benign PET, with 1 being aneuploid, and 6 of 15 malignant PET, with 4 being aneuploid. We conclude from these results that the ploidy pattern of PET allows no discrimination between benign and malignant tumours but may provide prognostic information on the aggressiveness of malignant PET.