Clinicopathological features of intraductal papillary mucinous neoplasms of the pancreas: an emphasis on predictors of malignancy

Yoon, Won Jae; Lee, Jun Kyu; Park, Joo Kyung; Lee, Sang Hyub; Ryu, Ji Kon; Kim, Yong Tae; Yoon, Yong Bum; Jang, Jin Young; Kim, Sun Whe; Kim, Woo Ho

Abstract

BACKGROUND: Intraductal papillary mucinous neoplasm of the pancrea (IPMN) is a newly recognized category of pancreatic exocrine tumors with a favorable prognosis. We conducted this study to evaluate clinicopathological features of IPMNs and to evaluate clinical factors associated with malignant IPMNs.
METHODS
We retrospectively evaluated 91 patients (55 males, mean age 61.6 years) who were diagnosed with IPMNs with histological confirmation from 1993 to 2004.
RESULTS
Fifty-eight cases were incidentally found, whereas 33 cases were symptomatic. Pathology revealed adenoma in 19 cases, IPMN with moderate dysplasia in 50 cases, noninvasive carcinoma in 8 cases, and invasive carcinoma in 14 cases. In main duct type (n=13) and combined type IPMNs (n=5), visible mucin secretion as seen on endoscopy indicated a borderline association with malignancy; a large tumor diameter (> or =30 mm) was associated with malignancy. In branch duct type IPMNs (n=73), the presence of symptoms or signs, the presence of mural nodules, a large tumor diameter (> or =27 mm) and a larger main pancreatic duct diameter (> or =4 mm) were associated with malignancy.
CONCLUSIONS
In IPMNs involving the main pancreatic duct, a large tumor diameter (> or =30 mm) is associated with malignancy. In branch duct type IPMNs, the presence of symptoms or signs, the presence of mural nodules, a large tumor diameter (> or =27 mm) and a large main pancreatic duct diameter (> or =4 mm) are associated with malignancy.