title: Atypical glomus tumor arising in the liver: a case report.
abstract: BACKGROUND
  Glomus tumors typically occur in the subcutaneous tissue of distal extremities, but rarely in visceral organs. Most glomus tumors are benign, while others have been reported to have malignant potential. Herein, a unique case of a liver glomus tumor with atypical histological features is reported.
  
  
  METHODS
  A 39-year-old man felt fullness in the epigastrium, and an enhanced computed tomography (CT) scan of the abdomen and pelvis revealed a 21-cm solid and cystic mass in the left liver lobe. The patient underwent a left hepatic lobectomy, and the tumor was pathologically identified as a glomus tumor with atypical histological features in the liver. This case is unique for three reasons. First, cases of glomus tumors in the liver are extremely rare. Second, this is the first report of a hepatic glomus tumor with histologically atypical features. Third, immunohistochemical staining showed focal positivity for synaptophysin. A literature review revealed that glomus tumors in visceral organs positive for synaptophysin show histological atypical features in most cases.
  
  
  CONCLUSIONS
  This is the first case of a glomus tumor with atypical histological features arising in the liver. This unique case and literature review yielded interesting findings and enabled us to postulate that synaptophysin positivity may be indicative of atypical histological features in glomus tumors arising in visceral organs.
authors.affiliation: Department of Pathology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Hirose
authors.affiliation: Department of Pathology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.|Department of Digestive Surgery and Surgical Oncology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-kogushi, Ube, Yamaguchi, 755-8505, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagano
authors.affiliation: Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Eguchi
authors.affiliation: Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.|Department of Regenerative Surgery, Fukushima Medical University, School of Medicine, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Marubashi
authors.affiliation: Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of Pathology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan. morii@molpath.med.osaka-u.ac.jp.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Morii
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D005918:Glomus Tumor / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D016708:Synaptophysin / Q000032:analysis / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; C569014:SYP protein, human; D016708:Synaptophysin