Secretoneurin in carcinoids of the appendix-immunohistochemical comparison with chromogranins A,B and secretogranin II

Abstract

Background: The aim of the present study was to investigate immunohistochemically the distribution of secretoneurin, a novel 33 amino acid peptide, in comparison to chromogranin A, chromogranin B, and secretogranin II in carcinoids of the appendix.

Materials and methods: Paraffin-embedded tissues from 47 carcinoids were incubated with antibodies specific for chromogranin A, chromogranin B, the secretogranin II derived peptide LF- 19, and secretoneurin.

Results: 44 tumors (94%) were positive for secretoneurin, whereas only 39 tumors (83%) were immunoreactive for chromogranin A. There was no significant correlation between neuropeptide expression and type of carcinoid, tumor size, vascular infiltration, serosal involvement or mesoappendiceal infiltration.

Conclusions: Our investigations revealed that secretoneurin is detected more frequently than chromogranin A in carcinoids of the appendix. This supports the theory that tumor cells of appendiceal carcinoids are of a different origin than other midgut carcinoids. No special tumor entity with a characteristic secretoneurin-chromogranin pattern could be identified.