APUD瘤是起源于APUD系统细胞的一种肿瘤。APUD细胞分布甚为广泛(见表),为有着共同超微结构和细胞化学特征的一群细胞。因具有含胺、能摄取胺前物质、含氨基酸脱羧酶,以及分泌多肽类激素的特征,故称这类细胞为APUD系统(Amine Precursor Uptake and decarb-oxylation System)。该系统的细胞现认为均有发生肿瘤的潜能,对起源于该系统的肿瘤统称Apudoma。 The APUD tumor is a tumor that originates from the cells of the APUD system. APUD cells are widely distributed (see table) and are a group of cells with common ultrastructural and cytochemical features. Because of the characteristics of containing amines, uptake of amine precursors, amino acid decarboxylase, and secretion of peptide hormones, these cells are called Amine Precursor Uptake and decarb-oxylation System. The cells of this system are now considered to have the potential to develop tumors, and tumors originating from this system are collectively referred to as Apudoma.