Immunohistochemical similarities between pancreatic mucinous cystic tumor and ovarian mucinous cystic tumor.

OBJECTIVE

Pancreatic mucinous cystic tumor (MCT(P)) and ovarian mucinous cystic tumor (MCT(O)) show common features. However, there are few studies showing a comparison of both types of tumor. We immunohistochemically studied both types of tumor to clarify their characteristics.

METHODS

Eight patients with MCT(P) and 21 patients with MCT(O) were examined. The tumors were immunohistochemically examined using antibodies against female sex hormone receptors (estrogen receptor, progesterone receptor, and alpha-inhibin), pancreatobiliary tissue markers (carbohydrate antigen 19-9 and DUPAN2) and cell cycle regulators (p27kip1 and phosphorylated retinoblastoma). Samples from 7 female patients with invasive pancreatic ductal carcinoma (DC), 8 female patients with normal pancreatic tissue, and 10 patients with normal ovarian tissue were also examined.

RESULTS

In the tumor epithelial cells, the expressions of DUPAN2 and p27/kip1 were similar between MCT(P) (38% and 88%, respectively) and MCT(O) (14% and 76%, respectively), but significantly different between both tumors and DC (100% and 0%). In the stromal cells, the expressions of estrogen receptor, progesterone receptor, alpha-inhibin, and p27/kip1 were similar between MCT(P) (63%, 75%, 50%, and 63%, respectively) and MCT(O) (57%, 71%, 81%, and 57%, respectively), but significantly different between both tumors and DC (0%, 0%, 0%, and 0%, respectively).

CONCLUSIONS

MCT(P) and MCT(O) have several immunohistochemical similarities and are significantly different from DC. The female sex hormone system may play a major role in the development of both MCT(P) and MCT(O). A frequent p27/kip1 expression level was associated with nonaggressive progression of both tumors.