title: Etiology of solitary extrapulmonary positron emission tomography and computed tomography findings in patients with lung cancer.
abstract: OBJECTIVE
  The aim of this prospective study was to assess the incidence and the nature of solitary extrapulmonary [18F] fluorodeoxyglucose (FDG) accumulations in patients with non-small-cell lung cancer (NSCLC) staged with integrated positron emission tomography and computed tomography (PET/CT) and to evaluate the impact on management.
  
  
  METHODS
  A total of 350 patients with NSCLC underwent whole-body PET/CT imaging. All solitary extrapulmonary FDG accumulations were evaluated by histopathology, further imaging, or clinical follow-up.
  
  
  RESULTS
  PET/CT imaging revealed extrapulmonary lesions in 110 patients. In 72 patients (21%), solitary lesions were present. A diagnosis was obtained in 69 of these patients, including 37 (54%) with solitary metastases and 32 (46%) with lesions unrelated to the lung primary. Histopathologic examinations of these 32 lesions revealed a second clinically unsuspected malignancy or a recurrence of a previous diagnosed carcinoma in six patients (19%) and a benign tumor or inflammatory lesion in 26 patients (81%). The six malignancies consisted of carcinoma of the breast in two patients, and carcinoma of the orbit, esophagus, prostate, and non-Hodgkin's lymphoma in one patient each. Benign tumors and inflammatory lesions included eight colon adenomas, four Warthin's tumors, one granuloma of the lower jaw, one adenoma of the thyroid gland, one compensatory muscle activity due to vocal chord palsy, two occurrences of arthritis, three occurrences of reflux esophagitis, two occurrences of pancreatitis, two occurrences of diverticulitis, one hemorrhoidal inflammation, and one rib fracture.
  
  
  CONCLUSIONS
  Solitary extrapulmonary FDG accumulations in patients with newly diagnosed lung cancer should be analyzed critically for correct staging and optimal therapy, given that up to half of the lesions may represent unrelated malignancies or benign disease.
authors.affiliation: Division of Thoracic Surgery, University Hospital, Raemistrasse 100, 8091 Zurich, Switzerland. didier.lardinois@usz.ch
authors.forename: Didier
authors.initials: D
authors.lastname: Lardinois
authors.forename: Walter
authors.initials: W
authors.lastname: Weder
authors.forename: Marina
authors.initials: M
authors.lastname: Roudas
authors.forename: Gustav K
authors.initials: GK
authors.lastname: von Schulthess
authors.forename: Michaela
authors.initials: M
authors.lastname: Tutic
authors.forename: Holger
authors.initials: H
authors.lastname: Moch
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Stahel
authors.forename: Hans C
authors.initials: HC
authors.lastname: Steinert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007249:Inflammation; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18