[Gastrointestinal carcinoid tumor--an immunohistochemical and histochemical study]

Fourteen gastrointestinal carcinoid tumors were studied by immunohistochemical and histochemical methods. Neuro-specific enolase (NSE) was detected in all 14 cases with patterns of homogeneously moderate to strongly diffuse cytoplasmic stain. 12 of 14 neoplasms (85.7%) were positive for Grimelius technic. 5 (35.7%) were positive for Masson-Fontana stain. The results indicate that the immunohistochemical demonstration of NSE is a marker more sensitive than the silver stain for gastrointestinal carcinoid tumors. Distribution and significance of silver stain are discussed.