Prognostic and immunohistochemical validation of the Capella classification of pancreatic neuroendocrine tumours: an analysis of 82 sporadic cases

Aims: To study the clinical outcome of 82 cases of pancreatic neuroendocrin e tumours classified according to the recent histological and prognostic cl assification of Capella. Methods and results: Eighty-two surgical cases of pancreatic neuroendocrine tumours were examined histologically with immunohistochemical staining of paraffin sections using streptavidin-biotin complex and application of anti bodies against chromogranin A and 10 hormonal peptides. Classification in f our groups correlated with long follow-up and outcome of these cases. Histo logical examination showed 30 group I, four group II, 41 group III and seve n group IV tumours. Twenty-one (70%) of group I tumours were insulinomas, w hereas 25% of group III tumours were glucagonomas and 25% were unclassified . Most group IV tumours were unclassified, showing no immunohistochemical s taining with any of the 10 hormonal peptides tested. Outcome was clearly co rrelated with tumour group. Among the 14 patients who died of the disease, four had group IV and 10 group III tumours. Thus, unclassified asymptomatic tumours without immunohistochemical staining had a poorer prognosis than a symptomatic tumours with staining. Conclusion: This study validates the Capella classification as easy to appl y and useful in predicting clinical outcome.