Long-term Follow-up of Intraductal Papillary Mucinous Neoplasm of the Pancreas With Ultrasonography  Taketo Yamaguchi, Takeshi Baba, Takeshi Ishihara, Akitoshi Kobayashi, Kazuyoshi Nakamura, Hiroshi Tadenuma, Hiroshi Ito, Masaru Miyazaki, Hiromitsu Saisho  Clinical Gastroenterology and Hepatology  Volume 3, Issue 11, Pages 1136-1143 (November 2005) DOI: 10.1016/S1542-3565(05)00756-1 Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 1 (A), Changes in MPD diameter in retrospective group of patients (n = 11). (B) Changes in cyst diameter in retrospective group of patients (n = 16). (C) Changes in height of protruding lesion in retrospective group of patients (n = 27). Clinical Gastroenterology and Hepatology 2005 3, 1136-1143DOI: (10.1016/S1542-3565(05)00756-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 2 Survival of patients in the retrospective group distributed according to the histopathology of the tumors. –▾–, Benign IPMN; , CIS; , invasive cancer. There was a significant difference in survival rate between the benign IPMN and invasive cancer, and between CIS and invasive cancer (Log-rank test, P < .01). Clinical Gastroenterology and Hepatology 2005 3, 1136-1143DOI: (10.1016/S1542-3565(05)00756-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 3 A case of invasive cancer in a 74-year-old man. The patient complained of mild upper abdominal pain in 1997, and US was performed disclosing a diffusely dilated main pancreatic duct (MPD) of 2.9 mm in diameter (A). He was tentatively diagnosed as having chronic pancreatitis and was subjected to follow up by US. The diameter of the MPD was found to have increased to 3.4 mm in February 1999, and on the US examination in October 1999, it was 7.3 mm at the tail of the pancreas without the appearance of a protruding lesion, thus the patient continued to be conservatively followed up (B). The US procedure performed 6 months later in March 2000 disclosed a further enlarged MPD with an obvious protruding lesion (C, arrow). The patient was worked up using other evaluation techniques and was referred to surgery with the diagnosis of malignant IPMN. The histopathological examination of the resected specimen confirmed the diagnosis of invasive cancer derived from IPMN. Clinical Gastroenterology and Hepatology 2005 3, 1136-1143DOI: (10.1016/S1542-3565(05)00756-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 4 Changes of actual values of each US parameter in the prospective group: MPD diameter (A), cyst diameter (B), and protruding lesion (C). ○, Followed-up patients; •, operated-on patients. Clinical Gastroenterology and Hepatology 2005 3, 1136-1143DOI: (10.1016/S1542-3565(05)00756-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 5 Clinical course of all the patients depending on the presence or absence of malignant findings at the beginning of follow up. Note that 14 patients without malignant findings at the beginning of follow up, who were operated on because the values of US parameters increased, showed an extremely high frequency of malignancy, whereas none of the 10 patients whose values of US parameters had not increased developed malignant IPMNs. (+), positive; (−), negative. * MPD diameter >7.4 mm, cyst diameter >32 mm, protruding lesion >3.9 mm. †Criteria established based on the results of this study. ‡Histopathological diagnosis. Clinical Gastroenterology and Hepatology 2005 3, 1136-1143DOI: (10.1016/S1542-3565(05)00756-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions