CT evaluation of gastroenteric neuroendocrine tumors: relationship between ct features and the pathologic classification.

Objective: The objective of our study was to compare the CT features of gastroenteric neuroendocrine neoplasms (GE-NENs) with the pathologic classification and to analyze the correlation between the CT features and classification of GE-NENs.
Materials and Methods: Fifty-six cases of pathologically and immunohisto-chemically proven GE-NENs, including 25 cases of neuroendocrine tumors (NETs) (i.e., G1 and G2 tumors) and 31 cases of neuroendocrine carcinomas (NECs) (i.e., G3 tumors and mixed adenoneuroendocrine carcinomas) were studied. We analyzed various CT features of the primary tumor, nodal status, and metastasis and compared these features with pathologic grading.
Results: The CT features that favor NEC over NET include larger tumor size (> 4.0 cm), transmural invasion, circumscribed tumor with both intra- and extraluminal involvement, circumferential growth, areas of cystic change or necrosis, ulceration, mesenteric fat infiltration, and lymphadenopathy, with p values of 0.044, 0.002, 0.024, 0.008, 0.002, 0.007, 0.002, and < 0.001, respectively. The CT features that do not distinguish between the two types of GE-NENs include tumor boundary, growth pattern, degree of enhancement, adjacent organ invasion, distant organ metastasis, and peritoneal seeding, with p values of 0.277, 0.153, 0.672, 1.000, 0.159, and 0.877, respectively.
Conclusion: CT can be useful in the classification of GE-NENs.