title: Imaging of gastrointestinal melanoma metastases: Correlation with surgery and histopathology of resected specimen.
abstract: OBJECTIVE
  To assess the appearance of gastrointestinal melanoma metastases on CT and PET/CT and evaluate the diagnostic value of CT and PET/CT compared with surgery and histopathology.
  
  
  METHODS
  We retrospectively included 41 consecutive patients (aged 56.1 ± 13.5 years) with gastrointestinal melanoma metastases who underwent preoperative imaging (CT: all, PET/CT: n = 24) and metastasectomy. Two blinded radiologists assessed CT and PET/CT for gastrointestinal metastases and complications. Diagnostic accuracy and differences regarding lesion detectability and complications were assessed, using surgical findings and histopathology as standard of reference.
  
  
  RESULTS
  Fifty-three gastrointestinal melanoma metastases (5.0 ± 3.8 cm) were confirmed by surgery and histopathology. Lesions were located in the small bowel (81.1 %), colon (15.1 %) and stomach (3.8 %), and described as infiltrating (30.2 %), polypoid (28.3 %), cavitary (24.5 %) and exoenteric (17.0 %). Fifteen patients (37 %) had gastrointestinal complications. Higher complication rates were associated with large and polypoid lesions (p ≤ .012). Diagnostic accuracy was high for CT and PET/CT (AUC ≥ .802). For reader B (less experienced), CT yielded lower diagnostic accuracy than PET/CT (p = .044).
  
  
  CONCLUSIONS
  Most gastrointestinal melanoma metastases were located in the small bowel. Large and polypoid metastases were associated with higher complication rates. PET/CT was superior for detection of gastrointestinal melanoma metastases and should be considered in patients with limited disease undergoing surgery.
  
  
  CONCLUSIONS
  • Gastrointestinal melanoma metastases (GI-MM) are rare but often cause serious gastrointestinal complications. • Early detection of GI-MM is important to prevent complications and guide surgery. • PET/CT is superior to CT for detection of GI-MMs. • PET/CT should be considered for patients with limited disease before surgical resection.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany. ahmed.e.othman@googlemail.com.
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Othman
authors.affiliation: Department of Dermatology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, 72076, Tuebingen, Germany.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Eigentler
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Bier
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Pfannenberg
authors.affiliation: Institute of Pathology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, 72076, Tuebingen, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Bösmüller
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Eberhard Karls University Tuebingen, University Hospital Tuebingen, 72076, Tuebingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Thiel
authors.affiliation: Department of Dermatology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, 72076, Tuebingen, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Garbe
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Klumpp
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D006801:Humans; D007421:Intestine, Small / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D064847:Multimodal Imaging; D015588:Observer Variation; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods; D011300:Preoperative Care; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms; D013274:Stomach Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: CT; Computed tomography; Gastrointestinal metastases; Melanoma; PET/CT