title: Pathomorphological changes after radiofrequency ablation in the liver.
abstract: Radiofrequency ablation (RFA) has become a widespread treatment option for liver carcinoma. There is limited knowledge regarding the macroscopic and histomorphological changes of induced lesions. Twelve domestic pigs underwent RFA using a Starburst XL device with ablation diameter of 3 cm. One animal died within 24 h, two animals were killed after 2 weeks, and nine after 4 weeks. Their livers were used for macroscopic and histological investigation. Six human liver resection specimens after previous treatment with RFA were also investigated. In pig samples, acute RFA change showed a necrosis zone demarcated by resorption zone with granulocytes and hyperemia. In subchronic and chronic RFA change, the zone of thermofixation was followed by a fibrous capsule and a liver reaction zone. Small blood vessels in the lesions showed damage involving endothelial destruction and thrombosis. Larger vessels within the lesions were observed with intact vessel walls, surrounded by a rim of vital hepatocytes. In the human samples, tumor-infiltrating lymphocytes were reduced (CD3+ cells: 8.4 +/- 3.7/10 high-power fields (HPF); CD4+ cells: 4.2 +/- 1.9/10 HPF), whereas the number of histiocytes was found to be increased (CD68+ cells: 15.5 +/- 9.02/10 HPF). The recognition of thermofixation and the process of resorption of the RFA lesion is important for the interpretation of biopsies and surgical resection specimens.
authors.affiliation: Institute of Pathology, Clemenshospital Münster, Germany.
authors.forename: Hans-Udo
authors.initials: HU
authors.lastname: Kasper
authors.forename: Christopher
authors.initials: C
authors.lastname: Bangard
authors.forename: Axel
authors.initials: A
authors.lastname: Gossmann
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Dienes
authors.forename: Dirk Ludger
authors.initials: DL
authors.lastname: Stippel
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000209:etiology; D013552:Swine
chemical_list: D014408:Biomarkers, Tumor