Goblet Cell Carcinoid of the Appendix
Definition
- Cytologically bland appendiceal neoplasm consisting of cohesive clusters composed of cells exhibiting intracytoplasmic mucin and scattered cells witih neuroendocrine differentiation
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 may appear poorly differentiated or undifferentiated
- Cytologically bland
- Mitotic figures infrequent
- Many cells resemble goblet cells or signet ring cells
- Mucin positive cytoplasm
- Nucleus displaced by mucin
- Rare to scattered neuroendocrine cells always present
- <25% of cells
- Seen on synaptophysin or chromogranin stains
- Cohesive clusters and cords of cells
- Discohesive, single cells rare
- Cohesive cord or linear pattern usually seen within invaded muscularis propria
- Well formed gland lumens not seen
- Paneth cells and foci resembling Brunner glands have been reported
- Frequently little architectural distortion of appendix
- Invasion of appendix wall shows scant desmoplasia
- Invasion frequently circumferential and lateral
- May not form a well defined tumor mass
- Perineural invasion common
- Pools of extracellular mucin may be seen
- Clusters of bland goblet cells may be in and around the pools
- Regional lymph node involvement is frequent (19%)
- Extra-appendiceal spread is frequent (33%)
- Usually to right colon, peritoneal surfaces and ovary
- Hematogenous metastases rare
- The presence of any of the following features suggests a diagnosis of carcinoma ex-goblet cell carcinoid
- Irregular large clusters or sheets of cells
- Discohesive cells
- Significant cytologic atypia
- Desmoplastic response to invasion
- Presence of poorly differentiated or undifferentiated carcinoma
- One small series of combined GCC and classical carcinoid reported (Chetty 2010)
- This may represent a collision tumor as incidental classical carcinoids are not rare
- Goblet cell carcinoid essentially arises only in the appendix
- There are rare reports of GCC that claim an origin elsewhere in the gastrointestinal tract
Robert V Rouse MD
Teri A Longacre MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/last update : 7/12/10, 1/18/15
