ADENOSQUAMOUS CARCINOMA ARISING IN A MUCINOUS CYSTADENOMA OF THE PANCREAS

Background: Approximately 500 cystic neoplasms of the pancreas have be en reported, and among these the mucinous pancreatic cystadenomas are known to have malignant potential. We report a rare case of a mucinous cystadenoma containing adenosquamous carcinoma. Methods: We studied t he histochemical and immunohistochemical staining characteristics of t he tumor by staining with hematoxylin/eosin, Alcian Blue/Periodic Acid Schiff, and with immunoperoxidase-labelled antibodies against carcino embryonic antigen, epithelial membrane antigen, low and high molecular weight cytokeratins, the proliferation antigen Ki-67, and the tumor s uppressor antigen p-53. The K-ras oncogene was analyzed by direct sequ encing. Results: This case illustrates the usual presentation and feat ures of this unusual tumor-a middle aged woman with abdominal pain and no history of alcohol abuse or abdominal trauma. The mucinous cystic tumor of her pancreas was composed predominantly of benign epithelium with areas of a malignant component that were identified by thorough s ampling. Conclusion: We discuss the nomenclature of these neoplasms an d suggest that continuing efforts to subclassify mucinous cystic pancr eatic tumors histologically may not be necessary, since the tumors are all histologically similar and are malignant or have malignant potent ial, and for all, treatment should include resection. (C) 1997 Wiley-L iss, Inc.