Goblet Cell Carcinoid of the Appendix

Supplemental Studies

Marker	Pure GCC Areas	Signet Ring Type of Ca ex-GCC	Poorly Differentiated Type of Ca ex-GCC
Synaptophysin	100% of cases, rare to 25% of cells	Generally negative	Generally negative
Chromogranin	100% of cases, rare to 25% of cells	Generally negative	Generally negative
CDX2	no data	no data	no data
CK7	Variable	no data	no data
CK20	100%	no data	no data
p53	Negative	Positive	Positive
MUC1	Negative	Positive	Positive
MUC2	Positive	Negative	Negative

Other neuroendocrine markers have been reported positive also
Neuroendocrine cells are positive with both argentaffin and argyrophil stains