A True Splenic Cyst

An Immunohistologic Study of Lining Cell of the Cyst

Abstract

A 26-year-old woman complained of a tumor in the left hypochondrial region. The diagnosis of a splenic cyst was preoperatively made by CT, angiography and splenic scintigraphy. The spleen with its cyst was resected en bloc. The specimen weighed 1, 800g and measured 20×18×12cm. Histopathological examination revealed a true cyst, lined by a single layer of flattened cells. In order to determine the origin of the true splenic cyst we performed an immunohistochemical examination. Both keratin and vimentin as mesothelial markers and cancer antigen (CAl25) also showed positive staining. However neither epithelial membrane antigen (EMA) as an epithelial marker, nor factor-VIII-related antigen as an endothelial marker, was stained. From the above results this true sprenic cyst is considered to be of mesothelial origin.