Intraductal papillary mucinous neoplasms of the pancreas: clinicopathological features and long term outcome related to histopathological group.

Background/aims: To investigate the clinicopathological features of intraductal papillary mucinous neoplasms and evaluate the prognosis between histopathological groups.

Methodology: Retrospective review of 55 consecutive patients operated between 1991 and 2006, analysis of clinicopathological features and survival.

Results: Group I comprised of 9 mild and 14 moderate dysplasias, group II of 11 carcinomas in situ and group III of 21 invasive cancers. Age, diabetes, anorexia and jaundice were significantly more frequent in group III. Thirty-two patients (58.2%) presented main duct type which was more frequently associated with invasive carcinoma. Mean tumoral size progress from group I to group III (26.1mm vs. 27.4mm vs. 32.0mm p=0.015) as the mean size of the pancreatic duct (6.7mm vs. 7.9mm vs. 11.5mm p=0.008). Median follow-up was 154 months with 5-year survival rate of 60.7 %. For group I, II and III it was 76.3 %, 100 % and 25.8 % respectively (p=0.00007). Lymph node positivity was associated with poor outcome: 44.1% vs. 0% (N0 vs. N+) (p=0.0019).

Conclusions: The prognosis of non-invasive intraductal papillary mucinous neoplasms of the pancreas is favourable. For patients with invasive cancer, nodal invasion is a factor of worst prognosis.