title: Adenocarcinomas of unknown primary (ACUP) of the mediastinum mimicking lymphoma: CT findings at diagnosis and follow-up.
abstract: OBJECTIVE
  To describe the computed tomography (CT) features at diagnosis and after treatment of adenocarcinoma of unknown primary (ACUP) mimicking lymphoma of the mediastinum.
  
  
  METHODS
  Fifteen patients with pathologically proven ACUP and with primarily mediastinal involvement were initially referred to the Hematologic Department of our institution with a suspected diagnosis of lymphoma, and accounted for our study population. Presenting symptoms and baseline biological values were analyzed. All thoraco-abdominal CT studies were reviewed for the location and size of the mediastinal involvement and associated findings. Follow-up chest CT was performed in 14 patients after radiotherapy, chemotherapy or surgical treatment.
  
  
  RESULTS
  The most frequent CT feature was a large anterior and middle mediastinal mass (67%), with no calcification. Associated findings included the presence of lung nodules (40%), compression of large mediastinal vessels (33%) and pleural effusion (27%). Follow-up CT, performed in 14 cases, suggested partial or complete responses in 7 patients (50%) 4 weeks after the treatment onset.
  
  
  CONCLUSIONS
  Mediastinal ACUP is a differential diagnosis of large mediastinal masses and is frequently associated with lung nodules and mediastinal vascular compression.
authors.affiliation: Department of Radiology, Centre Hospitalo-Universitaire Henri Mondor, Imagerie Medicale, 51 Avenue du Marechal de Lattre de Tassigny, 94010 Créteil, France.
authors.forename: Leonie Claudine
authors.initials: LC
authors.lastname: Sorgho-Lougue
authors.forename: Alain
authors.initials: A
authors.lastname: Luciani
authors.forename: Hicham
authors.initials: H
authors.lastname: Kobeiter
authors.forename: Laurent
authors.initials: L
authors.lastname: Zelek
authors.forename: Caroline
authors.initials: C
authors.lastname: Malhaire
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Deux
authors.forename: Bernard
authors.initials: B
authors.lastname: Brun
authors.forename: Pascal
authors.initials: P
authors.lastname: Piedbois
authors.forename: Alain
authors.initials: A
authors.lastname: Rahmouni
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000628:therapy; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000628:therapy; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging*; D015996:Survival Rate; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome