title: CT and MRI findings of thymic carcinoid.
abstract: OBJECTIVE
  To evaluate the CT and MRI findings of thymic carcinoid and to compare these findings with previously published findings of thymoma.
  
  
  METHODS
  11 cases of pathologically proven thymic carcinoid were reviewed retrospectively. Three patients had typical carcinoid, and eight patients had atypical carcinoid. The characteristics of the tumours and related thoracic abnormalities were assessed in each case on CT and/or MRI by two chest radiologists. The final decisions on the findings were reached by consensus.
  
  
  RESULTS
  Thymic carcinoids were more likely to have a large mass (ranging from 18 to 105 mm), irregular contours (n = 8), heterogeneous intensity on T2weighted images (n = 6; eight patients underwent MRI), heterogeneous enhancement (n = 9) and local invasion (n = 7). A necrotic or cystic component was identified in seven patients (one typical carcinoid and six atypical carcinoids). Lymphadenopathy was seen in four patients. Septum, capsule, haemorrhage and calcification were seen in three patients, two patients, two patients and one patient, respectively, with atypical carcinoid.
  
  
  CONCLUSIONS
  Thymic carcinoids tend to have a high prevalence of large masses, irregular contours, heterogeneous intensity on T2weighted images, heterogeneous enhancement and local invasion on CT and/or MRI. A necrotic or cystic component is often seen in atypical carcinoid. Advances in knowledge: Radiologic features of thymic carcinoid mimic those of high-risk thymomas and/or thymic carcinomas.
authors.affiliation: 1 Department of Radiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Shimamoto
authors.affiliation: 2 Department of Clinical Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ashizawa
authors.affiliation: 3 Department of Radiology, Sasebo City General Hospital, Sasebo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kido
authors.affiliation: 1 Department of Radiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: 4 Department of First Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagayasu
authors.affiliation: 5 Department of First Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.affiliation: 6 Department of Second Internal Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mukae
authors.affiliation: 7 Department of Pathology, Nagasaki Prefecture Shimabara Hospital, Nagasaki, Japan.
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: 8 Department of Radiology, Japanese Red Cross Nagasaki Genbaku Hospital, Nagasaki, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ohtsubo
authors.affiliation: 9 Department of Pathology, Japanese Red Cross Nagasaki Genbaku Hospital, Nagasaki, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Shigematsu
authors.affiliation: 10 Department of Radiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nakazono
authors.affiliation: 11 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hidetake
authors.initials: H
authors.lastname: Yabuuchi
authors.affiliation: 1 Department of Radiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
mesh_terms: D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013950:Thymus Gland / Q000000981:diagnostic imaging; D013953:Thymus Neoplasms / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*