title: Clinical correlations with (18)FDG PET scan patterns in solid pseudopapillary tumors of the pancreas: still a surgical enigma?
abstract: BACKGROUND
  There are limited numbers of PET studies of solid pseudopapillary tumors (SPT) of the pancreas.
  
  
  METHODS
  We reviewed the medical records of 37 patients who underwent resection of pancreatic SPT and had been preoperatively evaluated by (18)F-FDG PET or PET/CT scan. Immunohistochemical analysis of glucose transporter-1 (GLUT-1) and hexokinase II (HK-II) was performed.
  
  
  RESULTS
  SPT could be categorized into five types according to the morphologic characteristics observed in PET images. Type I (hot FDG uptake in the entire tumor portion) was the most frequent (13, 34.2%), followed by type IV (focal uptake, 12, 31.6%), II (focal defect, 8, 21.1%), III (multiple and geographic uptake, 3, 7.9%), and V (total defective type, 1, 2.6%). The SUVmax in the solid portion of the SPT was 5.3 ± 4.1. The clinical pattern of FDG uptake in SPT was not associated with histopathologic features suggesting malignant potential. The SUVmax of SPT followed a pattern according to pattern of FDG uptake (R(2) = 0.203, p = 0.055), and was significantly associated with adjusted tumor volume (p = 0.001). GLUT-1 was not expressed in SPT, and only eight patients (12.3%) showed mild to moderate expression of HK-II, which was associated with the clinical pattern of SPT in PET images (p < 0.05).
  
  
  CONCLUSIONS
  SPT of the pancreas could be categorized according to the morphologic patterns observed in PET images. The clinical significance of FDG uptake, glucose metabolism, and clinical usefulness of PET scan in SPT need to be further investigated, and thus this tumor remains a surgical enigma.
authors.affiliation: Department of Surgery, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea. Electronic address: cmkang@yuhs.ac.
authors.forename: Chang Moo
authors.initials: CM
authors.lastname: Kang
authors.affiliation: Department of Radiology, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea.
authors.forename: Arthur
authors.initials: A
authors.lastname: Cho
authors.affiliation: Department of Pathology, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea.
authors.forename: Hyunki
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Chung
authors.affiliation: Department of Surgery, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea.
authors.forename: Ho Kyoung
authors.initials: HK
authors.lastname: Hwang
authors.affiliation: Department of Surgery, Bundang CHA Hospital, CHA University College of Medicine, Seongnam, Republic of Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Surgery, Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic, Institute of Gastroenterology, Severance Hospital, Seoul, Republic of Korea. Electronic address: wjlee@yuhs.ac.
authors.forename: Woo Jung
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D051272:Glucose Transporter Type 1 / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000201:enzymology / Q000473:pathology; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
chemical_list: D051272:Glucose Transporter Type 1; D019275:Radiopharmaceuticals; C495677:SLC2A1 protein, human; D019788:Fluorodeoxyglucose F18; D006593:Hexokinase
keywords: 2-Deoxy-2-[(18)F] fluoro-d-glucose ((18)F-FDG); GLUT-1; Pancreatectomy; Positron emission tomography (PET); Solid pseudopapillary tumor; Tumor Metabolism