The diagnosis of pancreatic mucinous cystic neoplasm and associated adenocarcinoma in males: An eight-institution study of 349 patients over 15 years

Background: Per WHO, 2000 classification, pancreatic mucinous cystic neoplasms (MCN) are defined by presence of ovarian stroma, and are primarily located in the pancreatic body/tail of females. The incidence of MCN and associated malignancy in males, since, standardization of MCN diagnostic-criteria is unknown.

Methods: MCN resections from 2000 to 2014 at eight institutions of the Central-Pancreas-Consortium were included, and divided into early (2000-2007) and late (2008-2014) time-periods. Primary aim was to characterize MCN and associated adenocarcinoma/high-grade-dysplasia (AC/HGD) in males versus females over time.

Results: Of 1667 resections for pancreatic cystic lesions, 349 pts (21%) had MCNs: 310 (89%) female, 39 (11%) male. Patients were equally divided between early (n = 173) and late (n = 176) time-periods. MCN in male-patients decreased over time (early: 15%, late: 7%; P = 0.036), as did pancreatic head/neck location (early: 22%, late: 11%; P = 0.01). MCN-associated AC/HGD was more frequent in males versus females (39 vs. 12%; P < 0.001). The overall rate of MCN-associated AC/HGD remained stable (early: 17%, late: 13%; P = 0.4), and was identical in males (39%) over both time-periods. Males with AC/HGD had more LN-positive disease versus females (57 vs. 22%; P = 0.039).

Conclusions: As the diagnostic-criteria of MCN have standardized over time, MCN diagnosis has decreased in males and head/neck location. Despite this, MCN-associated adenocarcinoma/high-grade dysplasia has been stable and remains high in males. Any male with suspected MCN, regardless of location, should undergo resection.