Carcinoma Ex-goblet Cell Carcinoid of the Appendix
Definition
- Biphasic appendiceal neoplasm exhibiting both areas of typical GCC and areas of infiltrating adenocarcinoma
Alternate/Historical Names
- Adenocarcinoid
- Crypt cell carcinoma
- Mucinous carcinoid
Diagnostic Criteria
- Classification is based on the appearance of the primary tumor, not on the metastases
- Metastases often appear more poorly differentiated or undifferentiated
- Typical goblet cell carcinoid is at least focally present
- Typical cohesive nests of bland goblet cells may be only very focally preserved
- Rare to scattered neuroendocrine cells always present
- Seen on synaptophysin or chromogranin stains
- Present in typical goblet cell carcinoid areas
- Less reliably seen in carcinomatous components
- Carcinoma is present with the following features (criteria proposed by Tang 2008)
- Signet ring cell type
- Infiltrating signet ring cell carcinoma is present with at least one of the following features
- Goblet cells / signet ring cells in irregular large clusters
- Confluent sheets of cells indicates poorly differentiated carcinoma type, see below
- Discohesive single file or single cell infiltration
- Desmoplastic response
- Significant cytologic atypia
- Irregular hyperchromatic nuclei
- Goblet cells / signet ring cells in irregular large clusters
- Poorly differentiated type exhibits at least one of the following features
- Confluent sheets of atypical cells
- May or may not be signet cells
- >1 low power field or >1 mm2 of conventional type adenocarcinoma, usually poorly differentiated or undifferentiated
- May form glands
- Confluent sheets of atypical cells
- Features that may be shared by both types, but are not seen in pure goblet cell carcinoid
- Cytologically atypical signet ring cells
- Discohesive single file or single cell infiltration
- Desmoplastic response
- Significant cytologic atypia
- Irregular hyperchromatic nuclei
- Infiltrating signet ring cell carcinoma is present with at least one of the following features
- Regional lymph node involvement frequent
- 73% in signet ring cell type
- 100% in poorly differentiated type
- Extra-appendiceal spread to right colon, peritoneal surfaces and ovary is frequent
- 88% in signet ring cell type
- 100% in poorly differentiated type
- Hematogenous metastases rare
- Signet ring cell type
Robert V Rouse MD
Teri A Longacre MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting : 7/12/10, last update 12/21/14
