Mucinous cystadenoma of the pancreas with predominant stroma creating a solid tumor

Abstract

Background: Mucinous cystic neoplasm (MCN) of the pancreas is basically cystic epithelial neoplasm, unilocular or multilocular, occurring almost exclusively in women.

Case presentation: A 51-year-old female presented with a pancreatic mass incidentally found on the abdominal computed tomography. She underwent distal pancreatectomy. The sectioned surface of the pancreas revealed a circumscribed, whitish gray ovoid firm mass with some cystic spaces. Microscopically, glandular or small cystic structures were scattered in the predominant stroma creating a solid appearance. The subepithelial stromal component was composed of cytologically bland looking spindle cells, which resembled ovarian stroma. The stromal cells were reactive to CD 34, vimentin, progesterone receptor and calretinin. The microscopy was consistent with mucinous cystadenoma of the pancreas.

Conclusion: This case of mucinous cystadenoma of the pancreas showed very interesting pathology: It was solid rather than cystic, and accompanied by abundant benign transitional epithelia, which was a very unusual and novel finding in the mucinous cystic neoplasm of the pancreas.

Figure 1

Contrast enhanced abdominal computed tomography showing an ill defined mass revealing faint inhomogeneous low density in the body of the pancreas.

Figure 2

A. Macroscopic photograph of the tumor. Sectioned surface reveals a non-encapsulated, circumscribed, gray-white, firm, solid mass with partially lobulate margin and irregular small cysts. B. Low power view of microscopic features of the tumor. Cystic or glandular epithelial components are set in abundant dense stroma (hematoxylin and eosin, × 40)

Figure 3

Microscopic photograph of the tumor. A. Cystic structure is lined by benign columnar mucinous epithelial cells (arrow). Subepithelial stroma is composed of bland looking spindle cells (asterisk) mimicking ovarian stroma (hematoxylin and eosin, × 200). B. Stromal cells are immunoreactive against calretinin (× 200). C. Stromal cells are reactive against progesterone receptor (× 400). D. Columnar epithelia are accompanied by intestinal metaplasia with scattered goblet cells (right) as well as pseudopyloric metaplasia (left) (hematoxylin and eosin, × 200). E. Scattered endocrine cells (arrows) are highlighted by reactivity to chromogranin A (× 400). F. Cysts are lined by benign transitional-type epithelium, beneath which the stroma is hyalinized (hematoxylin and eosin, × 200). G. Transitional cells are immunoreactive to high molecular weight cytokeratin (× 400).