Rectal Carcinoid / Well Differentiated Neuroendocrine Neoplasm / Tumor
Clinical
- Five year survival for rectal carcinoid depends upon extent at presentation
- Localized at presentation 81%
- Regional spread at presentation 47%
- Liver metastases at presentation 18%
- Deaths due to disease continue to occur beyond 5 years
- Carcinoid syndrome is rare even if the liver is involved by metastases
- 13% of patients also have a non-endocrine neoplasm, usually gastrointestinal adenocarcinoma
- Histopathologic features are predictive of behavior
- Benign
- Non-functioning
- Well differentiated
- ≤1 cm in greatest dimension
- Confined to mucosa and submucosa
- No involvement of muscularis propria
- No vascular invasion
- Uncertain malignant behavior
- As for benign, but with:
- >1 but ≤2 cm in greatest dimension and/or
- Vascular invasion
- Low grade malignant
- Non-functioning and well differentiated, with
- Invasion of muscularis propria or beyond and/or
- Metastasis and/or
- >2 cm in greatest dimension (not uniformly accepted)
- OR, functioning and well differentiated
