Infarction of extralobar pulmonary sequestration after blunt trauma

A rare case of torsion and infarction of an extralobar pulmonary sequestration with MR, CT, and surgical correlation

Extralobar pulmonary sequestration is a rare congenital pulmonary malformation that may present early in life or remain asymptomatic. Here we present a case of torsion of an extralobar pulmonary sequestration on its vascular pedicle. Although the patient's initial symptomatology suggested intraabdominal pathology, the correct preoperative diagnosis was determined in large part by the lesion's MRI characteristics, which strongly suggested tissue infarction.

Pulmonary sequestration: What the radiologist should know

Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura (extralobar), lacking normal communication with the tracheobronchial tree and receiving its arterial supply by one or more systemic vessels. It is the second most common congenital lung anomaly according to pediatric case series, but its real prevalence is likely to be underestimated, and imaging plays a key role in the diagnosis and treatment management of the condition and its potential complications. We will give a brief overview of the pathophysiology, clinical presentation and imaging findings of intra- and extralobar pulmonary sequestration, with particular reference to multidetector computed tomography as part of a powerful and streamlined diagnostic approach.

Two adult cases of extralobar pulmonary sequestration: A non-complicated case and a necrotic case with torsion

Background

This case report describes two cases of extralobar pulmonary sequestration in adults with and without torsion/necrosis.

Case Reports

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.

Infarction of an extralobar pulmonary sequestration in a young child: diagnosis and excision by video-assisted thoracoscopy

A 4-year-old male presented with abdominal pain. A computed tomography scan of the abdomen was negative, but a pleural effusion and mass was noted in the lower left thorax. Video-assisted thoracoscopic surgery revealed the mass to be a rare case of extralobar pulmonary sequestration that had undergone infarction.