Correlation of computed tomography imaging features and pathological features of 41 patients with pancreatic neuroendocrine tumors.
OBJECTIVE
Pancreatic neuroendocrine tumors (PNET) are relatively rare. Here, we present clinical and pathological characteristics of PNETs to show a relationship between computed tomography (CT) imaging and the 2010 World Health Organization (WHO) classification.


METHODS
We retrospectively reviewed the records of 41 PNET patients who were treated between 2002 and 2012. All tumors were classified as neuroendocrine tumor (NET) grade 1 (G1), NET grade 2 (G2), or neuroendocrine carcinoma (NEC) grade 3 (G3) on the basis of the 2010 WHO classification system.


RESULTS
Twenty-five tumors were classified as G1, 11 as G2, and five as G3. Mean sizes of the G1, G2 and G3 tumors were 1.84 ± 0.54, 4.90 ± 0.84, and 5.62 ± 1.18 cm, respectively, (P < 0.01). A PNET is typically hypervascular and exhibits contrast enhancement on enhanced CT. Higher percentage of G1 tumors demonstrated typical imaging and showed a significantly greater distinct mass compared with G2 and G3 tumors.


CONCLUSIONS
Although PNET has many imaging features that appear on CT, G2 and G3 tumors often show atypical imaging features, particularly with large sizes and/or ill-defined features, when compared with G1 tumors. If a PNET has atypical imaging features, possibility of malignancy should be considered.
Masashi
M
Utsumi
Yuzo
Y
Umeda
Kosei
K
Takagi
Kuise
K
Takashi
Daisuke
D
Nobuoka
Ryuichi
R
Yoshida
Susumu
S
Shinoura
Hiroshi
H
Sadamori
Takahito
T
Yagi
Toshiyoshi
T
Fujiwara
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D018358:Neuroendocrine Tumors / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D010190:Pancreatic Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden