title: A case of embryonal sarcoma of the liver mimicking a hydatid cyst in an adult.
abstract: An undifferentiated (embryonal) liver sarcoma (ULS) originates from a primitive mesenchymal cell, with a predilection for childhood and very rare occurrence in adults. We report a case of a ULS that was incidentally found in a 53-year-old female. Our case was initially interpreted as a large hydatid cyst, which was later suspected to be a neoplastic lesion because its size was increasing and a solid portion was newly detected after shrinkage of the cyst following drainage. The patient underwent successful right hepatic lobectomy with complete resection, and is currently disease-free without adjuvant therapy. Although it is difficult to diagnose a hepatic cyst as a ULS due to its rare occurrence in adulthood and lack of specific findings, its possibility should be considered, especially when its size is increasing, because early diagnosis and curative resection are necessary for a favorable outcome.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Yoon
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Gi Hong
authors.initials: GH
authors.lastname: Choi
authors.forename: Young Nyun
authors.initials: YN
authors.lastname: Park
authors.forename: Joo Won
authors.initials: JW
authors.lastname: Chung
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
authors.forename: Chae Yoon
authors.initials: CY
authors.lastname: Chon