[Classification of neuroendocrine tumors and the effect on surgical technique]

Neuroendocrine tumors of the gastrointestinal tract are heterogenous regarding hormone production and tumor biology and have a varying disease course and survival time. In 1995 Capella et al. proposed a new classification of neuroendocrine tumors combining characteristics of the primary (i.e. histological differentiation, size, extension into surrounding tissues, hormonal activity and angioinvasion) and its suspected biological behavior (benign, uncertain, low-grade malignant, high-grade malignant). The extent of surgical therapy depends on the malignant potential of the primary tumor. To evaluate the usefulness of this classification in practical work neuroendocrine tumors have to be categorized by this classification and these data have to be correlated with the individual long-term course of patients.