Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Torsion of pulmonary sequestration, extralobar type
- Radiologic Findings
- Fig 1. Chest radiograph shows mass-like opacity in left lung base and blunting of a costophrenic angle, which suggests pleural effusion.
Fig 2. Axial precontrast CT image shows a wedge-shaped low attenuating mass-like lesion in the left lower paraspinal area.
Figs 3 and 4. Enhanced axial and coronal CT images demonstrate little enhancement of the mass-like lesion and a small amount of left pleural effusion. There is no pleural thickening nor nodularity. The feeding vessel was not demonstrated on enhanced CT images.
Ultrasonography shows a well-defined wedge shaped mass-like lesion without vascularity in the left hemithorax.
- Brief Review
- A 16-year old man was referred to our hospital for LUQ pain. CT shows a mass-like lesion with little enhancement in the left lower paraspinal area. USG demonstrated a well-defined wedge-shaped mass-like lesion without vascularity in the left paraspinal area. We suspected torsion of pulmonary sequestration based on the typical location of the lesion, clinical symptom, and imaging findings. VATS was performed and the lesion was finally diagnosed with torsion of pulmonary sequestration.
Pulmonary sequestration has been described as a congenital pulmonary malformation in which a mass of non-functioning lung tissue receives systemic arterial blood supply and does not have a demonstrable connection to the tracheobronchial tree. Pulmonary sequestrations are further divided into intralobar and extralobar sequestrations. The former is contained within the visceral pleura of another lobe, and the latter is contained in a separate pleural envelope. The extralobar sequestration is less common than the intralobar type, accounting for only 15-25% of all sequestrations.
CT is frequently used to evaluate the vascular anatomy of sequestration. Imaging findings of an extralobar sequestration include a homogeneous, well-circumcised mass of soft-tissue attenuation. Demonstration of a feeding vessel (most often from the thoracic or abdominal aorta) suggests the diagnosis of extralobar sequestration. The venous drainage is via the azygos vein, hemiazygos vein, or the IVC.
Torsion of sequestration is extremely rare. Torsion of pulmonary sequestration should be considered in the appropriate clinical setting even if the classic findings of a vascular pedicle are not demonstrated on cross-sectional imaging.
- References
- 1. FRAZIER, Aletta Ann, et al. Intralobar sequestration: radiologic-pathologic correlation. Radiographics, 1997, 17.3: 725-745.
2. FELKER, Richard E.; TONKIN, I. L. Imaging of pulmonary sequestration. AJR. American journal of roentgenology, 1990, 154.2: 241-249.
3. SHAH, Ricki; CARVER, Terrence W.; RIVARD, Douglas C. Torsed pulmonary sequestration presenting as a painful chest mass. Pediatric radiology, 2010, 40.8: 1434-1435.
- Please refer to
- Case 679 Case 471 Case 127
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- Keywords
- Extralobar Pulmonary Sequestration,