Solid pseudopapillary neoplasm of the pancreas: a rare and atypically aggressive disease among male patients.

Solid pseudopapillary neoplasm (SPN) of the pancreas is uncommon, has low metastatic potential, typically afflicts young females, and expresses progesterone receptors. In the rare male patient, its biologic behavior may be more aggressive and lethal. A retrospective case series analysis and literature review of SPN was performed to compare its clinical behaviors in males and females. The case series identified 11 patients of which only two were males. Ten patients underwent tumor resection with curative intent. The one operated male developed liver metastases 15 months postoperatively and subsequently died. The other male presented with advanced liver metastases and died 2 months later without operation. One female had regional lymph node metastases resected en bloc and all nine females are disease-free after a mean follow-up of 63.4 months. Analysis of 1014 patients reported in the literature revealed only 137 (13.5%) males. Males had a twofold higher incidence of metastases and a threefold higher death rate. In males, SPN has an atypically aggressive biology suggesting that progesterone and/or other sex hormones may have a role in oncoregulation.