title: Late emergence of contrast-enhancing fat necrosis mimicking tumor seeding after renal cryoablation.
abstract: Defining radiographic treatment success after percutaneous renal ablation is challenging due to variable ablation zone imaging findings over time. The present report describes two cases of progressively more evident enhancing soft-tissue nodules in the perinephric fat more than 2 years after cryoablation. Despite features concerning for tumor recurrence on computed tomography and magnetic resonance imaging, biopsies revealed fat necrosis in both cases. Renal ablation zone soft-tissue nodules can appear long after ablation, enhance with contrast medium, mimic applicator tract or ablation zone tumor seeding, and may require biopsy for confirmation of benignity.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10065. Electronic address: durackj@mskcc.org.
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Durack
authors.affiliation: Department of Radiology, Centre Léon Bérard, Lyon, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Richioud
authors.affiliation: San Diego Imaging, Sharp Memorial Hospital, San Diego, California.
authors.forename: James
authors.initials: J
authors.lastname: Lyon
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10065.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Solomon
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D003287:Contrast Media; D003452:Cryosurgery / Q000009:adverse effects*; D003937:Diagnosis, Differential; D005218:Fat Necrosis / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D007472:Iohexol; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D061330:Multidetector Computed Tomography; D009366:Neoplasm Seeding; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D007472:Iohexol; C112666:gadoversetamide
keywords: RCC; RF; radiofrequency; renal cell carcinoma