Hypervascular solid-appearing serous cystic neoplasms of the pancreas: Differential diagnosis with neuroendocrine tumours.
OBJECTIVE
To describe imaging findings of arterial hypervascular solid-appearing serous cystic neoplasms (SCNs) of the pancreas on CT and MR and determine imaging features differentiating them from neuroendocrine tumours (NETs).


METHODS
We retrospectively identified 15 arterial hypervascular solid-appearing SCNs and randomly chose 30 size-matched pancreatic NETs. On CT, two radiologists in consensus assessed the size, morphology, and CT attenuation. On MR, predominant signal intensity and the amount of the cystic component on T2-weighted images and ADC maps were evaluated and compared using Fisher's exact and Student's t-test.


RESULTS
The mean SCN size was 2.6 cm (range, 0.8-8.3). The CT findings were similar between the two tumours: location, shape, margin, and enhancement pattern. SCNs were significantly more hypodense on non-enhanced CT images than NETs (P = .03). They differed significantly on MR: bright signal intensity (P = .01) and more than a 10% cystic component on T2-weighted images (P = .01) were more common in SCNs than in NETs. All SCNs showed a non-restrictive pattern on the ADC map, while NETs showed diffusion restriction (P < .01).


CONCLUSIONS
Arterial hypervascular solid-appearing SCNs and NETs share similar imaging features. Non-enhanced CT and MR images with T2-weighted images and ADC maps can facilitate the differentiation.


CONCLUSIONS
• Frequency of hypervascular solid-appearing SCNs was 7.3% among surgically confirmed SCNs. • Hypervascular solid-appearing SCN of the pancreas can mimic pancreatic NETs. • Unenhanced CT and MR features help to differentiate the two tumours.
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Hye Sun
HS
Park
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea. sykimrad@amc.seoul.kr.
So Yeon
SY
Kim
Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Seung-Mo
SM
Hong
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Seong Ho
SH
Park
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Seung Soo
SS
Lee
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Jae Ho
JH
Byun
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Jin Hee
JH
Kim
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Hyoung Jung
HJ
Kim
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
Moon-Gyu
MG
Lee
D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000098:blood supply / Q000000981:diagnostic imaging*; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
Diagnosis; Diagnostic imaging; Magnetic resonance imaging; Multidetector computed tomography; Pancreatic neoplasms