title: Hepatic schwannoma: imaging findings on CT, MRI and contrast-enhanced ultrasonography.
abstract: A primary benign schwannoma of the liver is extremely rare and is difficult to preoperatively discriminate from a malignant tumor. We compared the imaging and pathological findings, and examined the possibility of preoperatively diagnosing a benign liver schwannoma. A 72-year-old woman was admitted to our hospital because of a 4.6-cm mass in the liver. A malignant tumor was suspected, and a right hepatectomy was performed. After this, the diagnosis of a primary benign schwannoma of the liver was made through pathological examination. Contrast-enhanced ultrasonography (CEUS) with Sonazoid showed minute blood flows into the septum and solid areas of the tumor in the vascular phase; most likely due to increased arterial flow associated with infiltration of chronic inflammatory cells. In the postvascular phase, CEUS showed contrast defect of cystic areas and delayed enhancement of solid areas; most likely due to aggregation of siderophores. Because discriminating between a benign and malignant schwannoma of the liver is difficult, surgery is generally recommended. However, the two key findings from CEUS may be useful in discriminating ancient schwannoma by recognizing the hemorrhage involved in the secondary degeneration and aggregation of siderophores.
authors.affiliation: Division of Metabolism and Biosystemic Science, Department of Medicine, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ota
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Aso
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takahiro
authors.initials: T
authors.lastname: Einama
authors.forename: Koji
authors.initials: K
authors.lastname: Imai
authors.forename: Hidenori
authors.initials: H
authors.lastname: Karasaki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Sudo
authors.forename: Yosui
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Mituyoshi
authors.initials: M
authors.lastname: Okada
authors.forename: Yosihiko
authors.initials: Y
authors.lastname: Tokusashi
authors.forename: Toru
authors.initials: T
authors.lastname: Kono
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Miyokawa
authors.forename: Masakazu
authors.initials: M
authors.lastname: Haneda
authors.forename: Masahiko
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Furukawa
mesh_terms: D000368:Aged; D001706:Biopsy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005290:Ferric Compounds; D019786:Gadolinium DTPA; D006498:Hepatectomy; D006801:Humans; D007501:Iron; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D061330:Multidetector Computed Tomography; D009442:Neurilemmoma / Q000098:blood supply / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D010087:Oxides; D011237:Predictive Value of Tests; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; C073590:gadolinium ethoxybenzyl DTPA; D007501:Iron; D019786:Gadolinium DTPA