[Diagnosis and treatment of carcinoid tumors in the gastrointestinal tract].

Histopathologically and biologically, endocrine cell tumors in the gastrointestinal tract are divided into two groups: 1) carcinoid, a low-grade malignancy, and 2) endocrine cell carcinoma (synonymous with small cell carcinoma), a high-grade malignancy. Atypical carcinoid, which has increased histological atypia and proliferative activity, shows more aggressive biological behavior than classical carcinoid. As a rule, endocrine cell carcinoma should be resected surgically with dissection of lymph nodes and adjuvant therapy if needed, while carcinoid should be treated by endoscopic resection or localized resection without lymph node dissection. Classical carcinoid of more than 2.0 cm in size and atypical carcinoid should be treated more carefully because of the increased risk of vascular permeation or distant metastasis.