title: FDG-PET findings of Ameloblastoma: a case report.
abstract: BACKGROUND
  Ameloblastoma is a benign odontogenic neoplasm of the jaw, rarely presenting as a malignant tumor. Although it is very important to discriminate ameloblastoma from ameloblastic carcinoma in order to decide the appropriate operative procedure, this is difficult using conventional CT and MRI.
  
  
  METHODS
  We report a case of maxillar ameloblastoma in a 78-year-old man where FDG-PET/CT was useful for making this discrimination. CT demonstrated a 31 × 43 × 46-mm mass in the left posterior maxillary sinus with destruction of its posterior and lateral wall and alveolar bone. MRI demonstrated a hypo- to isointense heterogeneous pattern on T1WI, heterogeneous hyperintensity with a prominent high-signal spot on T2WI, high signal intensity on DWI reflecting restricted diffusion, and strong heterogeneous enhancement. Because FDG-PET/CT showed mild FDG uptake (SUVmax 2.40) by the mass, ameloblastoma, rather than ameloblastic carcinoma, was considered to be the correct diagnosis.
  
  
  RESULTS
  It appears that ameloblastic carcinoma shows intense FDG uptake, whereas ameloblastoma shows mild or moderate FDG uptake, and only rarely intense FDG uptake. Our experience suggests that FDG-PET/CT may be effective for discriminating ameloblastoma from ameloblastic carcinoma. Especially, in cases showing mild FDG uptake, benign ameloblastoma would seem the most likely diagnosis.
  
  
  CONCLUSIONS
  FDG-PET/CT may be useful as an adjunctive modality for diagnosis, treatment planning and surveillance of ameloblastoma and ameloblastic carcinoma.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Seno
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kitajima
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Inokuchi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Nibu
authors.affiliation: Department of Diagnostic Pathology, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Department of Radiology, Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ejima
authors.affiliation: Department of Radiology, Division of Radiation Oncology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Sasaki
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Sugimoto
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017 Japan.
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
keywords: 18F-fluorodeoxyglucose (FDG); Ameloblastoma; CT; MRI; PET