title: Two adult cases of extralobar pulmonary sequestration: A non-complicated case and a necrotic case with torsion.
abstract: BACKGROUND
  This case report describes two cases of extralobar pulmonary sequestration in adults with and without torsion/necrosis.
  
  
  METHODS
  Non-complicated extralobar pulmonary sequestration was found incidentally in a 50-year-old asymptomatic woman (Case 1), diagnosed with the presence of a branching structure in a mass lesion and blood supply from the right inferior phrenic artery. Another case of a 38-year-old woman presented with a sudden onset of back pain caused by extralobar pulmonary sequestration with torsion/necrosis (Case 2). A 4-cm fusiform mass in the paravertebral region showed enhancement in the peripheral rim only, and no feeding artery. These were the same as it had been reported typical findings in extralobar pulmonary sequestration with necrosis. On magnetic resonance imaging, the masses in both cases showed inhomogeneous low signal and branching high signal on T2-weighted images. That was characteristic for a stroma without dilated alveoli as a solid part and dilated alveoli as fluid regions.
  
  
  CONCLUSIONS
  By comparing those two cases, we came to a conclusion that only T2-weighted imaging reflects the native structure, even after infarction. Although differentiation from a cystic tumor with hemorrhage or infection can be problematic, inhomogeneous low signal and branching high signal on T2-weighted images may help us distinguish extralobar pulmonary sequestration from other cystic lesions.
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Takeuchi
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Ono
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Toyooka
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Chest Surgery, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shigematsu
authors.affiliation: Department of Pathology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohta
authors.affiliation: Department of Radiology, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sagoh
keywords: Bronchopulmonary Sequestration; Necrosis; Torsion, Mechanical