Case Report
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Sep 21, 2012; 18(35): 4967-4972
Published online Sep 21, 2012. doi: 10.3748/wjg.v18.i35.4967
Hepatic schwannoma: Imaging findings on CT, MRI and contrast-enhanced ultrasonography
Yu Ota, Kazunobu Aso, Kenji Watanabe, Takahiro Einama, Koji Imai, Hidenori Karasaki, Ryuji Sudo, Yosui Tamaki, Mituyoshi Okada, Yosihiko Tokusashi, Toru Kono, Naoyuki Miyokawa, Masakazu Haneda, Masahiko Taniguchi, Hiroyuki Furukawa
Yu Ota, Kazunobu Aso, Ryuji Sudo, Yosui Tamaki, Mituyoshi Okada, Masakazu Haneda, Division of Metabolism and Biosystemic Science, Department of Medicine, Asahikawa Medical University, Asahikawa 078-8510, Japan
Kenji Watanabe, Takahiro Einama, Koji Imai, Hidenori Karasaki, Toru Kono, Masahiko Taniguchi, Hiroyuki Furukawa, Division of Gastroenterologic and General Surgery, Department of Surgery, Asahikawa Medical University, Asahikawa 078-8510, Japan
Yosihiko Tokusashi, Naoyuki Miyokawa, Department of Pathology, Asahikawa Medical University, Asahikawa 078-8510, Japan
Author contributions: Ota Y contributed to this work mainly; Ota Y, Aso K, Watanabe K, Einama T, Imai K, Karasaki H, Sudo R, Tamaki Y, Okada M, Kono T, Haneda M, Taniguchi M and Furukawa H provided medical care; Ota Y, Aso K and Taniguchi M collected the images; Tokusashi Y and Miyokawa N diagnosed the patient pathologically; Ota Y and Taniguchi M wrote the paper.
Correspondence to: Masahiko Taniguchi, MD, Division of Gastroenterologic and General Surgery, Department of Surgery, Asahikawa Medical University, Asahikawa 078-8510, Japan. m-tani@asahikawa-med.ac.jp
Telephone: +81-166-682503 Fax: +81-166-682193
Received: February 29, 2012
Revised: May 12, 2012
Accepted: May 26, 2012
Published online: September 21, 2012
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.

Keywords: Liver schwannoma; Contrast-enhanced ultrasonography; Liver resection