Flow and image cytometric study of pancreatic neuroendocrine tumours: frequent DNA aneuploidy and an association with the clinical outcome.

Eighteen pancreatic neuroendocrine (NE) tumours were analysed for nuclear DNA content by image cytometry (ICM) and flow cytometry (FCM). The DNA indices (DIs) obtained by ICM were somewhat higher than those obtained by FCM, but a major disagreement was present only in 1 case. Thirteen patients had been followed up at least for 6 years after the diagnosis or until death. At 6 years of follow-up all 4 patients with a tumour with a DI greater than or equal to 1.8 by ICM had died from their NE tumour or had metastatic disease, whereas all 9 patients with a smaller DI had no evidence of the disease (P = 0.001). The DIs calculated from the FCM data also correlated well with the final outcome (P = 0.01). A high incidence of DNA aneuploidy was found by both methods in histologically and clinically benign NE tumours; 12 (67%) were DNA aneuploid by FCM and 16 (89%) by ICM. It is concluded that pancreatic NE tumours are frequently DNA aneuploid, and both cytometric DNA methods give prognostic information in these tumours. The presence of DNA aneuploidy should not be considered as a sign of malignant behaviour in pancreatic NE tumours, whereas a large DI is associated with poor prognosis.