Combined production of mucus, amines and peptides by goblet-cell carcinoids of the appendix and ileum.

Goblet-cell carcinoids are particular mucus-producing tumors combining features of typical carcinoids and adenocarcinomas. The immunoreactivity of five goblet-cell carcinoids of the appendix and one tumor of the ileum for 5-hydroxytryptamine (5-HT, serotonin), glucagon, somatostatin, substance P (SP), neuron-specific enolase (NSE), lysozyme, secretory component (SC) and carcino-embryonic antigen (CEA) was compared with that of the mucosa of the appendix (n = 24) and ileum (n = 12), and of typical carcinoids (appendix: n = 10; ileum: n = 3). The goblet-cell carcinoids were consistently lysozyme-, SC- and CEA-reactive and contained weakly NSE reactive endocrine cells, while typical carcinoids were lysozyme-, SC- and CEA-negative, but strongly NSE- reactive. Two goblet-cell carcinoids were glucagon-reactive, one displayed SP-reactivity, one malignant tumor was reactive to the alpha-chain of glycoprotein hormones; six of ten typical appendix carcinoids were SP reactive, as were the three typical ileum carcinoids. Using the immunogold technique combined with the alcian-blue reaction, the presence of 5-hydroxytryptamine (5-HT) and mucus was demonstrated within the same cell. These findings suggest histogenetic differences between goblet-cell carcinoids and typical carcinoids; the former are possibly derived from undifferentiated stem cells, whereas the latter probably arise from endocrine cells in the mucosal stroma.