Solid pseudopapillary tumor of the pancreas: E-cadherin, β-catenin, CD99 new useful markers with characteristic expression (about two case reports)

Abstract

Solid pseudopapillary neoplasm of the pancreas is a rare tumor that has favorable prognosis. It poses frequently diagnostic challenges. We describe two cases of solid pseudopapillary tumor of the pancreas managed in our department between 2007 and 2011. Two females have mean age of 36.5 years. Clinical presentation include: abdominal pain, bloating and palpable abdominal mass. Tumor is localized in the head of the pancreas in one case and in the tail in the other case. The mean size of the mass was 6 cm (range: 5 to 7 cm). Surgical treatment was performed in two cases. Histological examination confirms the diagnosis of solid pseudopapillary tumor of the pancreas. Immunohistochemical analysis was concordant to the literature data especially concerning CD99 which positivity was in dot, loss of positivity of E-cadherin and nuclear staining of β-catenin. CD10 and α-1-antitrypsin were also positive. One patient was dead 3 days postoperative and neither cancer recurrence nor distant metastases were detected on the follow up of the other. However, solid pseudo-papillary tumor of the pancreas has a distinctive histological appearance; some cases are problematic requiring the use of immunohistochemistry to distinguish it from other pancreatic neoplasm which prognosis is different.

Keywords: CD99; E-cadherin; Solid pseudo-papillary tumor of the pancreas; case report; β-catenin.

Figure 1

solid pseudopapillary neoplasm; pseudo-papillary component with vessels surrounded by loosely cohesive cells

Figure 2

solid pseudopapillary neoplasm; cystic pattern with large hemorrhagic changes and foamy cells

Figure 3

solid pseudopapillary neoplasm; the neoplastic cells show nuclear immunolabelling for β-catenin

Figure 4

solid pseudopapillary neoplasm; diffuse intracytoplasmic dot-like imunoreactivity for CD99