title: F-18 FDG PET detection of a medullary thyroid carcinoma in a patient with metastatic colonic cancer; literature review.
abstract: OBJECTIVE
  We report a case of a medullary thyroid carcinoma discovered by F-18 fluorodeoxyglucose-positron emission tomography (F-18 FDG PET).
  
  
  METHODS
  A 73-year-old man with a history of surgical removal of sigmoid colon cancer underwent F-18 FDG PET to search for distant metastases and / or local recurrence because of elevated CEA level and new episode of occlusion. F-18 FDG PET images showed increased focal FDG uptake in the right lobe of the thyroid. Thyroid ultrasound showed one thyroid nodule in each lobe.
  
  
  RESULTS
  The fine needle aspiration result was suspicious and calcitonin level was elevated. The subject underwent thyroidectomy without lymph node dissection. The pathology showed a 14 mm medullary thyroid carcinoma. There was no germline mutation of RET.
  
  
  CONCLUSIONS
  F-18 FDG PET can detect primitive or secondary malignant thyroid tumors. Thus, thyroid incidentaloma revealed by 18 FDG PET uptake always necessitates careful evaluation.
authors.affiliation: Department of Endocrinology, Diabetology and Metabolic Disease, Avicenne Hospital, Paris XIII University (CRNH), 93009 Bobigny cedex, France. regis.cohen@avc.aphp.fr
authors.forename: R
authors.initials: R
authors.lastname: Cohen
authors.forename: H
authors.initials: H
authors.lastname: Bihan
authors.forename: G
authors.initials: G
authors.lastname: des Guetz
authors.forename: P
authors.initials: P
authors.lastname: Wind
authors.forename: A
authors.initials: A
authors.lastname: Martin
mesh_terms: D000368:Aged; D044963:Biopsy, Fine-Needle; D002116:Calcitonin / Q000032:analysis; D002272:Carcinoembryonic Antigen / Q000032:analysis; D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D003110:Colonic Neoplasms / Q000473:pathology* / Q000628:therapy; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D013965:Thyroidectomy; D014463:Ultrasonography
chemical_list: D002272:Carcinoembryonic Antigen; D019788:Fluorodeoxyglucose F18; D002116:Calcitonin