Intraductal papillary mucinous tumors of the pancreas comprise 2 clinical subtypes: differences in clinical characteristics and surgical management.

HYPOTHESIS Intraductal papillary mucinous tumors (IPMTs) of the pancreas may be meaningfully construed as representing 2 clinically distinct subtypes: main duct tumors (MDT) and branch duct tumors (BDT). DESIGN Retrospective study. SETTING University hospital from January 1988 through December 1994. PATIENTS AND INTERVENTION We reviewed diagnostic findings and late results of surgical treatment in 30 patients with IPMT. RESULTS The tumor was located in the head of the pancreas more often in BDT than in MDT (65% [11/17] and 23% [3/13], respectively). Of the 13 patients with MDTs, 12 (92%) had intraductal papillary adenocarcinoma (noninvasive and minimally invasive types) and/or carcinoma in situ (carcinoma in situ: low papillary and/or flat tumor cells), and 3 (23%) had stromal invasion. Of the 17 patients with BDTs, 5 (29%) had intraductal papillary adenocarcinoma and/or carcinoma in situ. Two pancreatoduodenectomies and 8 pylorus-preserving pancreatoduodenectomies were performed in 10 of the 17 patients with BDTs, distal pancreatectomy in 7 patients with MDTs, and total pancreatectomy in 4 patients with MDTs. The 5-year survival rates were 47% for MDT and 90% for BDT. Four of 6 patients with MDTs who died had local recurrence. One patient died of liver metastasis and 1 of esophageal cancer. Only 1 patient with BDT of the 2 who died had recurrent disease. CONCLUSIONS Intraductal papillary mucinous tumors may be composed of 2 clinically distinct subtypes: MDTs and BDTs. Initially, although distal pancreatectomy can be recommended for most MDTs, the need for cancer-free margins in this more aggressive type may necessitate total pancreatectomy. Pylorus-perserving pancreatoduodenectomies is recommended for most BDTs, but, because these tumors are more often adenomas, a good prognosis can be expected.