Cytologic diagnosis of hepatobiliary cystadenoma with mesenchymal stroma during intraoperative consultation: A case report

Background: Hepatobiliary cystadenoma with mesenchymal stroma (HCMS) is a rare cystic tumor characterized by a layer of mucinous cuboidal to columnar epithelium situated on top of a basement membrane resting on an ovarian-like stroma. Cytologic features of this entity have not been extensively studied. We present a case of HCMS with emphasis on cytologic material obtained at the time of intraoperative consultation (IOC). Case: A 51-year-old woman had partial resection of a liver cyst. Seven months later she sought further medical attention and presented for surgical reevaluation and reexcision of the same lesion. Initial computed tomography revealed a multiloculated liver cyst. Five months after reexcision the lesion recurred and was again excised. During IOC, scrape cytology revealed both biliary epithelial and mesenchymal stromal cells in a cystic background. Permanent sections showed histologic features of HCMS. To the best of our knowledge, this is the first cytologic description of such a neoplasm to include both epithelial and mesenchymal stromal elements. Conclusion: The use of scrape cytology during IOC can be a fast and effective way of identifying both the epithelium and mesenchymal stroma when HCMS is in the differential diagnosis of a cystic liver lesion.