title: FDG PET and PET/CT for the detection of the primary tumour in patients with cervical non-squamous cell carcinoma metastasis of an unknown primary.
abstract: In patients with a neck metastasis from an unknown primary with non-squamous cell cancer (non-SCC) histology, the primary is often located outside the head and neck area. We retrospectively evaluated 326 patient records and found 14 patients with non-SCC neck lymph node metastasis from an unknown primary undergoing whole body F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) with or without coregistered computed tomography (PET/CT). The PET or PET/CT findings were verified by pathological work-up, additional imaging tests, and clinical follow-up. PET detected pathological FDG uptake suspicious for the primary in eight patients. PET or PET/CT findings were true positive in seven patients, true negative in 4, false positive in 1, and false negative in two patients. In one patient PET/CT revealed a synchronous ovarian carcinoma. The results suggest that whole body imaging with FDG PET and PET/CT can be useful to identify unknown primaries of non-SCC origin. However, the work-up of patients undergoing PET or PET/CT in our study was very heterogeneous and the primary was more likely found in patients without extensive imaging before PET scanning. Further studies should evaluate if the histology of a neck nodal metastasis should influence the choice of the imaging method and the role of PET and PET/CT imaging for the work up of patients with a non-SCC neck lymph node metastasis of an unknown primary.
authors.affiliation: Interne Klinik Dr. Argirov, Kempfenhausen am Starnberger See, Muenchner Strasse 23-29, 82335, Berg, Germany.
authors.forename: Stefan A M
authors.initials: SA
authors.lastname: Paul
authors.forename: Sandro J
authors.initials: SJ
authors.lastname: Stoeckli
authors.forename: Gustav K
authors.initials: GK
authors.lastname: von Schulthess
authors.forename: Gerhard W
authors.initials: GW
authors.lastname: Goerres
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis* / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000556:secondary; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18