Essence Of Ovarian-type Stroma In Mucinous Cystic Neoplasms Of The Liver And Pancreas

OBJECTIVE: Ovarian-type stroma of hepatic mucinous cystic neoplasms (HMCN)and pancreatic mucinous cystic neoplasms (PMCN) plays a definitive role in differentialdiagnosis. This study clarified the histological characteristics and immunohistochemicalfeatures of the stroma in order to improve the cognitive ability of the disease and reducemisdiagnosis.METHODS: In total,25patients with HMCN and25patients with PMCN werecollected from PLA General Hospital. All the cases were surgical specimens, andconfirmed by the pathologist. Clinical features of the disease were summarized andmorphological characteristics of the ovarian-type stroma was observed by microscopy.Immunohistochemical stains were performed using smooth muscle actin (SMA),calponin, h-caldesmon and progesterone receptor (PR)with the stroma.RESULTS: The liver and pancreatic mucinous cystic tumors were almost femalepatients with an average age of47and44yesrs respectively. The ovarian-type stromawas abundant or scarce and packed closely or loosely under light microscope. Thehyalinization of the spindle cells which were very common could be in anyplace. Theblood capillaries proliferated and expanded considerably. In some cases nonspecificreactions which included foam cell aggregation, hemosiderin deposition, cholesterolcrystals, lipofuscin deposition and calcification could be found.All stroma of the50mucinous cystic neoplasms exhibited strong diffuse cytoplasmic staining with SMA andh-caldesmon. All stroma showed variably strong cytoplasmic staining with calponin.The spindle cells expressed variably strong positive nuclear staining with PR in39of50cases.CONCLUSIONS: The age in the histological grade of invasive mucinous cysticcarcinoma and high grade intraepithelial mucinous cystic neoplasms is older than in thehistological grade of the low grade and intermediate grade intraepithelial mucinouscystic tumors. The ovarian-type stroma of HMCN and PMCN is composed of smoothmuscle cells. This study shows statistically significant negative correlation between the expression of PR and the histological grade of MCNs.