Gastrointestinal neuro-endocrine tumors: retrospective study of 36 cases.

BACKGROUND: Neuroendocrine tumors (NETs) of the gastrointestinal tract are a heterogeneous group of tumors which have different malignant potential and evolution. The World Health Organization (WHO) has set up a new classification of gastrointestinal NETs in 2010. However, it does not evaluate the risk of malignancy for each tumor.

AIM: To evaluate the prognostic impact of the WHO classification in 2010 by reclassifying the tumor according to new recommendations and to identify histoprognostic factors to better predict changes.

METHODS: This is a descriptive retrospective study of 36 cases of gastrointestinal NETs, collected at the pathological anatomy department in Rabta hospital, over a period of 11 years from 2003 to 2013.

RESULTS: Our series included 11 NETs of Appendix, nine of the pancreas, seven of the small bowel, four of the stomach, three of the rectum, one of the colon and one of the esophagus. The mean age of patients across all sites, was 50.3 years old and the sex ratio was 0,44. The tumors were classified according to the 2010 WHO classification. They were divided into: G1 in 27 cases (75%); G2 in three cases (8.3%); G3 small cell carcinoma in two cases (5.6%); G3 large cell carcinoma in one case (2.8%) and mixed adeno-neuroendocrine carcinoma in three cases (8.3%).

CONCLUSION: Our study has shown limits of the latest 2010 WHO classification of NETs. The prognosis of these tumors could be better predicted by the evaluation of other histoprognostic factors and by the improvement of criteria defining histological degrees including tumor size.