title: Hepatic angiomyolipoma with special attention to radiologic imaging.
abstract: BACKGROUND
  Angiomyolipoma is a unique mesenchymal neoplasm composed of blood vessels as well as smooth muscle and adipose cells. The liver is a less common site of origin, and hepatic angiomyolipoma is often an incidental finding on diagnostic imaging or is identified on evaluation of nonspecific symptoms.
  
  
  METHODS
  We experienced four patients who were diagnosed histologically with hepatic angiomyolipoma. The preoperative diagnoses were angiomyolipoma in two patients, hepatocellular carcinoma in one, and cavernous hemangioma in one. Three patients were treated with hepatectomy (one laparoscopic and two open approaches), and the diagnosis was completed by histological investigation of the resected specimen. The remaining one was diagnosed from tumor needle biopsy. Diffusion-weighted magnetic resonance imaging (MRI) with respiratory triggering using b values of 0 and 800 s/mm(2) was employed. An apparent diffusion coefficient map was generated from b values of 0 and 800 s/mm(2) for calculation of the apparent diffusion coefficient. The apparent diffusion coefficient values were calculated as 3.66, 1.21, 1.80, and 0.91 in patients 1 to 4, respectively. In MRI imaging, fat component was clearly demonstrated with chemical shift imaging in three patients. Early venous return was detected in three patients with computed tomography angiography.
  
  
  CONCLUSIONS
  Fat component and early venous return are important for a correct diagnosis of hepatic angiomyolipoma. Unfortunately, apparent diffusion coefficient values in hepatic angiomyolipoma were overlapping with those in other benign and malignant tumors.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Kunitaka
authors.initials: K
authors.lastname: Kuramoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan ; Department of Multidisciplinary Treatment for Gastroenterological Cancer, Kumamoto University Hospital, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Beppu
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Namimoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Imai
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Nitta
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hashimoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Chikamoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Ishiko
authors.affiliation: Department of Surgical Pathology, Kumamoto University Hospital, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Iyama
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Ikeda
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City, Kumamoto 860-8556 Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
keywords: Apparent diffusion coefficient (ADC); Chemical shift imaging; Diffusion-weighted MRI; Early venous return; Hepatic angiomyolipoma