title: Fine-needle aspiration cytology and differential diagnoses of fibrolamellar hepatocellular carcinoma metastatic to the mediastinum: case report.
abstract: We report a case of fibrolamellar hepatocellular carcinoma (FL-HCC) that metastasized to the posterior mediastinum. The diagnosis was made on fine-needle aspiration biopsy (FNAB). The cytologic features were characterized by the presence of large, dishesive, polygonal cells with granular cytoplasm and well-defined cell outlines resembling oncocytes. Groups of neoplastic hepatocytes containing bile pigment were also noted. The diagnosis of FL-HCC in a metastatic site can pose diagnostic challenges on FNAB. The cytologic features overlap with a variety of tumors that have oncocytic features and also with melanoma and paraganglioma. Recognition of specific cytologic features of FL-HCC can facilitate accurate diagnosis in a metastatic site. The cytologic findings and differential diagnoses of FL-HCC that metastasized to the posterior mediastinum are discussed.
authors.affiliation: Departments of Pathology and Gastroenterology, University Hospitals of Cleveland, Case Western Reserve School of Medicine Cleveland, Ohio, USA. venetia.sarode@utsouthwestern.edu
authors.forename: Venetia R
authors.initials: VR
authors.lastname: Sarode
authors.forename: Rudy
authors.initials: R
authors.lastname: Castellani
authors.forename: Anthony
authors.initials: A
authors.lastname: Post
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology; D000328:Adult; D001707:Biopsy, Needle; D006528:Carcinoma, Hepatocellular / Q000556:secondary* / Q000601:surgery; D003937:Diagnosis, Differential; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000601:surgery; D016031:Liver Transplantation; D008297:Male; D008479:Mediastinal Neoplasms / Q000556:secondary* / Q000601:surgery; D008545:Melanoma / Q000473:pathology; D016609:Neoplasms, Second Primary; D010235:Paraganglioma / Q000473:pathology