大野 栄三郎¹, 廣岡 芳樹², 川嶋 啓揮¹, 林 大樹朗¹, 桑原 崇通¹, 石津 洋二¹, 本多 隆¹, 葛谷 貞二¹, 中村 正直¹, 後藤 秀実¹

Eizaburo OHNO¹, Yoshiki HIROOKA², Hiroki KAWASHIMA¹, Daijuro HAYASHI¹, Takamichi KUWAHARA¹, Yoji ISHIZU¹, Takashi HONDA¹, Teiji KUZUYA¹, Masanao NAKAMURA¹, Hidemi GOTO¹

¹名古屋大学大学院医学系研究科消化器内科学, ²名古屋大学医学部附属病院光学医療診療部

¹Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, ²Department of Endoscopy, Nagoya University Hospital

キーワード :

【BACKGROUND】
IPMNs present in various histopathological stages from benign to malignant lesions and the assessment of malignant potentials is still difficult. The International consensus guidelines 2012 for the management of IPMN and MCN states the importance of features of mural nodules and main duct involvement to consider surgery.
（PATIENTS AND METHODS）
Since January, 2001, 218 patients out of 711 with IPMNs examined by both contrast-enhanced（CE）EUS which could exclude the false mural nodule（MN）as avascular structure and Multidetector-row（MD）CT have been surgically treated according to our treatment indications. CE-EUS of the main lesion was performed using 16μL of Sonazoid^®. Pathological diagnosis was based on WHO criteria and we classified both high-grade dysplasia and invasive IPMC as malignancy. We defined“mural nodule”as the nodular projection with blood flow signal in CE-EUS and“MPD involvement”as the spread of papillary projections along with the MPD by CE-EUS image. We compared the CE-EUS findings and histopathological findings to assess the diagnostic accuracy of mural nodules and MPD involvement retrospectively.
【RESULTS】
The pathological diagnoses were 108 pts with low-intermediate dysplasia, 53 with high-grade dysplasia and 57 with invasive IPMC. The detection rate of mural nodules of the main lesion by CE-EUS and MDCT were 98.2％ and 50.0％ respectively. The detection rate of MPD involvement by CE-EUS and MDCT were 50.2％ and 34.5％ respectively. As comparison with histopathologcal findings, the sensitivity, specificity and accuracy for the diagnosis of MPD involvement were 80.9％，88.9％ and 84.4％ respectively.
【CONCLUSION】
CE-EUS may allow to exclude mucous clots and detect the true tumorous area in the IPMN lesion precisely. Mural nodules including lower papillary projection along with MPD diagnosed by CE-EUS may represent even very fine epithelial changes in IPMNs.