title: High 18F-FDG uptake in PMAH correlated with normal expression of Glut1, HK1, HK2, and HK3.
abstract: BACKGROUND
  Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushing's syndrome, characterized by functioning adrenal macronodules and variable cortisol production. Recently, we demonstrated a high 18F-FDG uptake in PMAH, an unexpected finding for a benign disorder.
  
  
  OBJECTIVE
  To investigate whether there is a correlation between 18F-FDG high uptake and the expression levels of the glycolytic pathway components GLUT1, HK1, HK2, and HK3 in PMAH.
  
  
  METHODS
  We selected 12 patients undergoing surgery for PMAH who had preoperatively undergone 18F-FDG PET/CT. mRNA and protein expression of the selected genes were evaluated in the adrenal nodules from patients who underwent surgery through quantitative RT-PCR and by immunohistochemistry, respectively.
  
  
  RESULTS
  SUVmax in PMAH was in the range of 3.3-8.9 and the adrenal size was in the range of 3.5-15 cm. A strong correlation between 18F-FDG uptake and largest adrenal diameter was observed in patients with PMAH. However, no correlation between 18F-FDG uptake and GLUT1, HK1, HK2, HK3 mRNA, and protein expression was observed.
  
  
  CONCLUSIONS
  High 18F-FDG uptake is observed in the majority of PMAH cases. However, 18F-FDG uptake in PMAH is independent of the expression levels of GLUT1, HK1, HK2, and HK3. Further investigation is required to elucidate the molecular mechanisms underlying increased 18F-FDG uptake in PMAH.
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil isadoracavalcante@gmail.com.
authors.forename: Isadora Pontes
authors.initials: IP
authors.lastname: Cavalcante
authors.affiliation: Departamento de Patologia, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Maria Claudia Nogueira
authors.initials: MC
authors.lastname: Zerbini
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Guilherme Asmar
authors.initials: GA
authors.lastname: Alencar
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Beatriz de Paula
authors.initials: Bde P
authors.lastname: Mariani
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular do Instituto de Radiologia, São Paulo, Brazil.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Buchpiguel
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil Instituto do Cancer de Sao Paulo (ICESP), São Paulo, Brazil.
authors.forename: Madson Queiroz
authors.initials: MQ
authors.lastname: Almeida
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Berenice Bilharinho
authors.initials: BB
authors.lastname: Mendonca
authors.affiliation: Unidade de Suprarrenal, Disciplina de Endocrinologia e Metabologia, Laboratório de Hormônios e Genética Molecular LIM42, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil Instituto do Cancer de Sao Paulo (ICESP), São Paulo, Brazil.
authors.forename: Maria Candida Barisson Villares
authors.initials: MC
authors.lastname: Fragoso
mesh_terms: D000311:Adrenal Glands / Q000000981:diagnostic imaging / Q000378:metabolism; D003480:Cushing Syndrome / Q000235:genetics* / Q000378:metabolism; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D015870:Gene Expression / Q000235:genetics*; D051272:Glucose Transporter Type 1 / Q000235:genetics* / Q000378:metabolism; D006593:Hexokinase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D060888:Real-Time Polymerase Chain Reaction; D014057:Tomography, X-Ray Computed
chemical_list: D051272:Glucose Transporter Type 1; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C472074:HK1 protein, human; D006593:Hexokinase
keywords: 18F-FDG; Cushing’s syndrome; PET; Primary macronodular adrenal hyperplasia; adrenal; adults; hyperplasia; monoclonal antibodies