title: Nested (ossifying) stromal epithelial tumor of the liver: case report.
abstract: Nested stromal-epithelial tumor (NSET) of the liver is an extremely rare primary hepatic tumor with uncertain malignant potential. To date, only 11 cases have been described. We describe the case of a 2 1/2-year-old girl with an incidental liver mass. The mass was discovered on follow-up abdominal imaging for asymptomatic hydronephrosis diagnosed on antenatal ultrasound. Needle biopsy showed a mixed stromal and epithelial process in a nested pattern, with foci of ossification and no significant pleomorphism or necrosis. The nest cells stained with WT-1, cytokeratin 18, and CD56. Ossifying stromal epithelial tumor of the liver was strongly suspected. The findings were confirmed in the subsequent partial hepatectomy specimen. To our knowledge, this is the 12th case of NSET in the English-language literature and the 3rd case of NSET associated with genitourinary system abnormalities. Possible associations with dysregulated WT-1 expression are discussed.
authors.affiliation: Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. karenm@hadassah.org.il
authors.forename: Karen
authors.initials: K
authors.lastname: Meir
authors.forename: Alexander
authors.initials: A
authors.lastname: Maly
authors.forename: Victoria
authors.initials: V
authors.lastname: Doviner
authors.forename: Eitan
authors.initials: E
authors.lastname: Gross
authors.forename: Michael
authors.initials: M
authors.lastname: Weintraub
authors.forename: Lionel
authors.initials: L
authors.lastname: Rabin
authors.forename: Orit
authors.initials: O
authors.lastname: Pappo
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D002675:Child, Preschool; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D053538:Keratin-18 / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018193:Neoplasms, Complex and Mixed / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology*; D025721:WT1 Proteins / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D019002:CD56 Antigen; D053538:Keratin-18; D025721:WT1 Proteins