Differential Diagnosis
Goblet Cell Carcinoid, Pure Carcinoma ex GCC, Signet Ring Cell Type Carcinoma ex GCC, Poorly Differentiated Carcinoma Type
Bland cytology
Atypical cytology
Atypical cytology
Cohesive clusters and cords
Discohesive cells with single cell infiltration
May have discohesive cells
No desmoplasia
Desmoplastic response to invasion
Desmoplastic response to invasion
Small clusters and cords, no poorly differentiated or undifferentiated carcinoma
Irregular large clusters, no poorly differentiated or undifferentiated carcinoma
May have confluent sheets of cells OR >1 low power field or >1 mm2 of conventional type adenocarcinoma, usually poorly differentiated or undifferentiated
Based on histopathologic findings in primary tumor
All must have at least focal typical goblet cell carcinoid
Based on Tang 2008
Goblet Cell Carcinoid
GI Tract Adenocarcinoma
Bland cytologic features
Atypical cytology
Chromogranin or synaptophysin positive (scattered)
Chromogranin and synaptophysin negative
No desmoplastic response
Desmoplastic response frequent
Rare mitotic figures
Mitotic figures frequently numerous
Cohesive nests and cords
Frequent single cell infiltration
No surface adenoma or in situ lesion
May have surface adenoma or in situ component
p53-, MUC1-, MUC2+
p53+, MUC1+, MUC2 only 5% positive
Appendiceal Carcinoid / Well Differentiated Neuroendocrine Cell Neoplasm Goblet Cell Carcinoid and/or Carcinoma ex-GCC
Chromogranin or synaptophysin positive
Chromogranin and synaptophysin stain rare to scattered cells only
No intracytoplasmic mucin (lumenal mucin may be present in tubular carcinoid)
Intracytoplasmic mucin in goblets
CK7 negative, CK20 variable
CK7 variable, CK20 100%
Rare mitotic figures at most
Mitotic figures may be numerous in carcinoma ex-GCC
Cohesive nests and cords
Single cell infiltration or sheet like growth in carcinoma ex-GCC
No desmoplasia
Desmoplasia may be present in carcinoma ex-GCC
