title: A case of liver hemangioma with markedly reduced tumor size after metformin treatment: a case report.
abstract: A 52-year-old man with a 9-year history of hepatic hemangioma was treated with the anti-diabetic drug metformin, resulting in complete remission of the tumor. In 2006, a hemangioma with diameter of 20 × 25 mm was detected incidentally in the liver. The results of imaging studies including ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) were all compatible with that of hepatic hemangioma. The patient consequently underwent imaging annually from 2006 to 2015. The tumor size increased slightly, to 30 × 35 mm in 2012; however, the general tumor characteristics in imaging were not changed. Beginning May 2012, metformin (750 mg/day) was administered because of an increase in blood sugar and hemoglobin A1c levels. After the start of metformin treatment, the tumor size on US gradually decreased. Finally, in October 2015, the tumor was no longer detected. Dynamic CT study also demonstrated markedly reduced tumor size, with a decrease of 2-3 mm in diameter. These results indicate that metformin treatment strongly suppressed cell proliferation in liver hemangioma. The anti-angiogenic effect of metformin was indicated as a possible cause of the reduction in tumor size.
authors.affiliation: Division of Internal Medicine, Toyoura Municipal Hospital, 16-1 Shinonome, Toyoura Town, Hokkaido, 049-5411, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Ono
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 1-1-1 Midorigaoka Higashi 2 Jo, Asahikawa, Hokkaido, 078-8510, Japan. k-sawada@asahikawa-med.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 1-1-1 Midorigaoka Higashi 2 Jo, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Okumura
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D006391:Hemangioma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D008687:Metformin
keywords: Anti-angiogenesis; Hepatic hemangioma; Metformin; mTORC1–VEGF pathway