Pulmonary sequestration with torsion necrosis in an 11-year-old child: a case report of thoracoscopic resection and multidisciplinary management

Abstract

Introduction and importance:

Pulmonary sequestration (PS) with torsion necrosis is extremely uncommon in children, and little literature exists regarding its diagnostic challenges and optimal surgical approach. The present case highlights the central role of multimodal imaging and minimally invasive techniques in the treatment of this potentially fatal condition.

Case presentation:

An 11-year-old boy presented with acute right-sided chest pain, fever (38°C), and dyspnea. Laboratory findings were leukocytosis (WBC 21.06 × 10⁹/L, normal range: 4.3–11.3 × 10⁹/L), raised CRP (70.29 mg/L, normal range: <10 mg/L), and D-dimer (0.746 mg/L, normal range: <0.256 mg/L). Contrast CT revealed a non-enhancing triangular mass (4.3 × 1.6 × 3.6 cm) adjacent to the right diaphragm, with pleural effusion and atelectasis. Doppler ultrasound revealed a hypovascular lesion; MRI ruled out neurogenic tumors. Emergency thoracoscopic exploration showed a torsioned PS (540° vascular twist) with hemorrhagic necrosis. Hem-o-lok clips were applied to resect the lesion, and the patient made a complete recovery without complications.

Clinical discussion:

PS-torsion is susceptible to diagnostic pitfalls with overlapping presentations of tumors and pneumonia. Recent literature emphasizes the use of CT and MRI for diagnosing vascular anomalies and non-enhancing lesions. Unlike past reports, the present case innovatively employed single-incision thoracoscopy and ultrasound-guided localization to reduce operative risks [evidence based on case reports (Level 4)]. Early intervention prevented hemorrhagic death and sepsis, consistent with guidelines recommending immediate resection for symptomatic PS.

Conclusion:

This case emphasizes the role of multidisciplinary referral and high-level imaging in the diagnosis of torsioned PS. Thoracoscopic resection is safe and effective in children and warrants further validation in larger patient populations.

Introduction

Pulmonary sequestration (PS), an uncommon congenital pulmonary malformation occurring in 20–30% of congenital lung lesions, is defined by nonfunctioning lung tissue perfused by anomalous systemic arteries instead of pulmonary vasculature^[1^]. Epidemiological research demonstrates a male predominance (male-to-female ratio: 1.5–2.0:1), with 80% of cases being diagnosed prior to age 13^[2,3^]. Although early detection has been improved by prenatal ultrasound screening, 30% or more of pediatric PS cases are atypical (e.g., recurrent pneumonia, hemothorax) and therefore lead to delays in diagnosis^[4^]. Recent multicenter cohort data show that 57.9% of PS cases are initially misdiagnosed as tumors or pneumonia due to similar clinical and radiological presentations, which highlights the urgent need for more advanced diagnostic algorithms^[3^].

HIGHLIGHTS

• An unusual pediatric case of pulmonary sequestration (PS) with 540° vascular torsion and hemorrhagic necrosis, successfully managed via thoracoscopy.

• Multimodal imaging (CT, Doppler, MRI) was crucial for preoperative diagnosis.

• Single-incision thoracoscopic resection was successfully performed and proved safe and effective in this child.

• This case supports conservative, minimally invasive management in pediatric PS.

The diagnostic gold standard is contrast computed tomography (CT) and magnetic resonance imaging (MRI), which have a combined 92% sensitivity and 88% specificity for the detection of abnormal vasculature^[5^]. However, the detection of torsion-induced ischemia can be challenging with standard CT protocols alone, particularly in cases with subtle or intermittent vascular compromise.

Past studies validate sweeping knowledge gaps in pediatric PS treatment. There were no reported cases of children undergoing vascular torsion, despite its life-threatening potential^[2^], as per a systematic review of 41 articles (2006–2022). Adult research suggests thoracoscopic resection as a less risky procedure compared to thoracotomy, but outcomes in children are absent, with minimally invasive procedures used in only 11% of the cases^[6^]. Moreover, the torsion pathomechanism – possibly because of diaphragmatic motion or explosive growth of the lesion – remains theoretical and has not been demonstrated in experimental models.

This publication bridges these gaps by reporting the first documented case of pediatric PS with 540° vascular torsion and hemorrhagic necrosis, confirmed by intraoperative exploration and histopathology. The concurrence of Doppler ultrasound and MRI findings aligns with current practice guidelines for multimodal imaging in atypical presentations. In addition, we implemented a single-incision thoracoscopic surgery approach, adapted from adult procedures, which served both diagnostic and therapeutic purposes in this case. This case provides a valuable educational example for early recognition and minimally invasive management of this rare but life-threatening condition in children.

The work has been reported in line with the SCARE criteria^[7^].

Case presentation

Demographics and chief complaint

An 11-year-old boy presented to the emergency department with a 4-day history of acute onset right-sided chest pain and 1-day fever (maximum temperature: 38°C). The pain was non-radiating, not associated with cough, hemoptysis, or vomiting. No history of past respiratory illness, trauma, or surgery was present.

Clinical history and physical examination

On arrival, vital signs were tachycardia (heart rate of 110 bpm), tachypnea (42 breaths/min), and normotension (blood pressure of 109/77 mmHg). Physical examination revealed decreased right-sided breath sounds, dullness on percussion of the right lower lung field, and absent tactile fremitus. Wheezes and crackles were not heard on auscultation.

Diagnostic and therapeutic timeline

Day 1: Admitted to the respiratory department with presumptive diagnoses of pneumonia and parapneumonic effusion. The possibility of a vascular malformation or sequestration was initially overlooked. Initiated empiric ceftriaxone (1.5 g/day) and oxygen therapy.

Day 2: Ultrasound-guided thoracentesis was performed due to suspected pleural effusion/empyema and yielded 45 mL of hemorrhagic fluid. Persistent leukocytosis prompted a multidisciplinary consultation.

Day 4: Contrast MRI ruled out neurogenic tumors but revealed avascular pulmonary tissue. The working diagnosis was PS with torsion.

Day 5: Routine shifted to thoracic surgery for urgent thoracoscopic exploration.

Laboratory findings

Peripheral blood tests upon admission showed leukocytosis (WBC: 21.06 × 10⁹/L; reference: 4.3–11.3 × 10⁹/L), neutrophilia (82.2%), and elevated inflammatory markers (C-reactive protein: 70.29 mg/L; erythrocyte sedimentation rate: 71 mm/h). Coagulation tests showed hyperfibrinogenemia (6.28 g/L; normal: 2.0–4.0 g/L) and elevated D-dimer (0.746 mg/L; normal: <0.256 mg/L). Pleural fluid analysis showed a hemorrhagic exudate (RBC: 1.484 × 10¹²/L; WBC: 8.104 × 10⁹/L). Tumor markers (NSE, AFP, CEA) and infection disease serologies (pneumonia mycoplasma, tuberculosis) were negative.

Imaging studies

Chest CT (non-contrast): Asymmetrical right pleural thickening, spindle-shaped pleural protrusion, and patchy consolidation of the right lower lobe, with encapsulated effusion or pneumonia being considered.

Contrast CT: Triangular non-enhancing mass (4.3 × 1.6 × 3.6 cm) abutting the right diaphragm, with compressive atelectasis (Fig. 1A and B). Thoracic ultrasound: Hypoechoic, avascular mass along the spine and diaphragm, with overlying pulmonary consolidation and turbid pleural effusion (Fig. 1C and D).

Figure 1.

Multimodal imaging findings in an 11-year-old boy with torsioned pulmonary sequestration. (A, B) Axial contrast-enhanced computed tomography (CT) images demonstrate a non-enhancing, triangular soft tissue mass (white arrows) in the right posterior hemithorax adjacent to the diaphragm. The lesion appears hypodense and poorly perfused, with mild surrounding pleural effusion and lower lobe atelectasis. (C, D) Corresponding thoracic ultrasound images reveal a well-defined, hypoechoic, avascular mass (white arrows) located near the posterior diaphragm. The lesion lacks internal vascular flow on Doppler assessment, supporting the diagnosis of hemorrhagic infarction due to vascular torsion.

Cardiac ultrasound: Normal cardiac structure and function, apart from vascular malformations. The initial non-contrast CT and clinical presentation led to a misdiagnosis of pneumonia, highlighting the diagnostic challenge in such atypical cases.

Surgical findings and intervention

A single-incision laparoscopic surgery technique was employed via a 2.5 cm utility incision in the sixth intercostal space along the mid-axillary line. A 5 mm 30-degree thoracoscope and articulating laparoscopic instruments were used for exploration and dissection. Intraoperative examination revealed a 4 × 3 × 2.5 cm necrotic mass in the right lower lobe adhering to the chest wall. The lesion’s feeding artery had a 540° torsion (Fig. 2A), with complete vascular occlusion. The torsioned vascular pedicle was carefully dissected and isolated. After detorsion, the feeding artery was ligated using Hem-o-lok clips and transected. The ischemic lung segment was then resected using an endoscopic stapler. The specimen was extracted in a protective bag through the single port. Histopathology revealed hemorrhagic necrosis (85% tissue involvement) with chronic inflammation and dilated aberrant vessels, consistent with PS (Fig. 2B and C).

Figure 2.

Intraoperative, gross, and histopathological findings of torsioned pulmonary sequestration. (A) Thoracoscopic intraoperative view showing the twisted feeding artery (black arrow) with 540° rotation and dark discoloration, consistent with vascular torsion and impaired perfusion. The surrounding lung parenchyma appears congested and necrotic. (B) Gross specimen of the resected extralobar sequestration, measuring approximately 4 × 3 cm, with an irregular, hemorrhagic, and necrotic external surface. (C) Hematoxylin and eosin (H&E) stained histopathology section at 100× magnification showing extensive hemorrhagic necrosis and dilated, thick-walled aberrant vasculature typical of pulmonary sequestration.

Postoperative course and follow-up

The patient had an uneventful recovery. Leukocyte count normalized by postoperative day 3 (WBC: 9.2 × 10⁹/L), and CRP decreased to 8.7 mg/L upon discharge (postoperative day 7). Chest radiography prior to discharge confirmed resolution of pleural effusion and complete re-expansion of the right lung.

The patient was followed up at 1 month, 3 months, 6 months, and 1 year postoperatively. At each visit, he remained asymptomatic, with no recurrence of chest pain, fever, or respiratory distress. Spirometry performed at the 1-month follow-up showed normal pulmonary function (FEV1: 98% predicted, FVC: 96% predicted). Subsequent spirometry at 6 months and 1 year demonstrated sustained pulmonary function within normal limits (FEV1: 99 and 101% predicted, respectively).

Chest CT performed at the 6-month follow-up revealed no residual lesion, no pleural thickening, and normal lung architecture without signs of adhesion or recurrence. The patient has resumed all normal physical activities, including sports, without limitation. The parents reported no readmissions or emergency visits during the follow-up period.

This medium-term follow-up confirms the effectiveness of thoracoscopic resection and the absence of recurrence or functional impairment, supporting the long-term safety of this minimally invasive approach in pediatric patients with PS.

Discussion

To our knowledge, this represents one of the few reported pediatric cases of PS with 540° vascular torsion and hemorrhagic necrosis, illustrating a severe yet manageable complication. While PS occurs more frequently as a recurrent infection or incidentally^[1^], acute torsion represents a diagnostic urgency similar to other acute thoracic emergencies and necessitates urgent intervention to prevent further ischemic complications^[2^]. The initial diagnostic approach included thoracentesis, which revealed hemorrhagic fluid, raising suspicion of vascular compromise or malignancy. However, the absence of malignant cells and the fluid’s exudative nature guided further imaging. Contrast CT did not identify the torsioned artery, consistent with prior reports showing that 30% of such cases lack vascular findings on routine imaging^[3^]. The combination of Doppler ultrasound (which demonstrated absent vascular flow, suggestive of ischemic changes) and MRI (which excluded tumors and confirmed tissue non-enhancement) was essential for preoperative planning. Although ultrasound alone could not diagnose torsion, its findings prompted urgent further imaging and surgical consultation, leading to timely intervention.

The decision to perform a thoracoscopic resection was based on the established benefits of minimally invasive surgery. A single-incision approach was chosen in this case, adapted from adult protocols. It enabled complete resection without conversion to thoracotomy. While some evidence in the literature suggests potential advantages for single-incision over multi-port VATS in reducing blood loss and postoperative pain in children^[5^]. Preoperative multimodal imaging, including contrast CT, Doppler ultrasound, and MRI, was instrumental in surgical planning. CT delineated the non-enhancing mass and its relationship to the diaphragm, Doppler confirmed avascularity suggesting torsion, and MRI excluded neurogenic tumors, collectively guiding the minimally invasive approach. Adapted from adult protocols, the single-port approach enabled complete resection without conversion, aligning with recent support for minimally invasive surgery in hemodynamically unstable patients^[7,8^]. Parenchyma-sparing surgery improved functional recovery and challenged the traditional lobectomy-based approach used in adults^[3^]. These findings are in agreement with Pi et al’s (2021) recommendation that conservative resection is sufficient in pediatric PS without malignant risk.

Several aspects of this case provide educational insights and differentiate it from typical presentations of PS. One, the proposed torsion mechanism – mechanical stress via diaphragmatic motion – differs from static vascular defects explained in earlier PS reports^[4^]. Intraoperative evidence of adhesions in the region around the diaphragm makes this hypothesis valid, consistent with experimental models establishing the relationship between shear stress and vascular torsion. Second, discordance between CT findings (lack of necrosis) and histopathology (85% hemorrhagic infarction) highlights the dangers of sole reliance on radiographic data, re-emphasizing the necessity of ultrasound-guided sampling in uncertain cases^[2^].

Patient perspective

At the 1-month postoperative follow-up, the child and his parents expressed high satisfaction with the treatment outcome. The mother emphasized the relief brought by multidisciplinary coordination: “Initially, we were terrified by the emergency surgery recommendation. But the surgeons, radiologists, and pediatricians worked seamlessly to explain how the twisted blood vessel caused the crisis using the CT and MRI images we already had.”

The child specifically noted the minimal scarring from the single-incision thoracoscopy: “I thought there would be a large incision, but it’s just a small line under my armpit which no longer hurts.” This observation directly correlates with the intraoperative technique described in the Case presentation section (single-port approach with Hem-o-lok clip ligation).

Additionally, the cosmetic advantage of single-incision thoracoscopy was subjectively appreciated by the patient and family, consistent with prior reports suggesting improved cosmesis and patient satisfaction compared to multi-port approaches. Although we did not employ a standardized cosmetic scale (e.g., Vancouver Scar Scale) for objective measurement, the minimal visible scarring aligns with the growing emphasis on minimally invasive techniques that reduce physical and psychological trauma in pediatric patients. Future studies may benefit from incorporating validated cosmetic outcome measures to further quantify these advantages.

The parents highlighted two unanticipated benefits: (1) Rapid functional recovery evidenced by normalized spirometry at 1 month (FEV1: 98% predicted), aligning with postoperative imaging showing complete lung re-expansion; (2) The diagnostic clarity provided by combined Doppler ultrasound and MRI, which they described as “finally getting answers after days of uncertainty.” These perspectives reinforce the Discussion’s emphasis on multimodal imaging and conservative parenchymal resection.

Despite these gains, two limitations warrant mention. First, the 48-h wait for preoperative MRI underscores the need for standardized imaging protocols for acute pediatric chest pain, like those promoted by Pi et al (2021). Second, while short-term outcomes are promising, long-term risks of residual adhesions or recurrence cannot be assessed – a limitation acknowledged in Li and Yu’s (2021) 5-year follow-up of thoracoscopic PS resections. Future studies should emphasize molecular profiling (e.g., NF-κB or HIF-1α immunohistochemistry) to demystify ischemia–reperfusion pathways and confirm risk-stratified protocols incorporating ultrasound avascularity scores and inflammatory markers^[6^]. Further, multicenter trials comparing single-incision with multi-port thoracoscopy in children are needed to establish evidence-based protocols and clarify their respective advantages, as current practice often relies on data extrapolated from adults^[7^].

Conclusion

This case illustrates the diagnostic advantages of multimodal imaging and supports the feasibility of thoracoscopic resection in pediatric PS, even in complex presentations such as vascular torsion. Further studies are needed to validate these observations and clarify the underlying pathophysiological mechanisms in larger pediatric cohorts.

Ethical approval

The case report was approved by the Ethics Committee of Baoding Children’s Hospital Affiliated to Capital Medical University [Approval No. 2023 Fast Review (Science) No. 55].

Consent

Informed written permission was received from the patient’s legal guardian for publication of this case report, as well as anonymized clinical data, imaging reports, and intraoperative photos. All recognizable information has been removed to maintain patient confidentiality in accordance with the International Committee of Medical Journal Editors (ICMJE) guidelines and the Declaration of Helsinki. The consent procedure explicitly stated the educational purpose of data sharing and the non-identifiable nature of published information. The authors confirm that this report complies with institutional ethics committee standards and all applicable laws on patient confidentiality.

Sources of funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author contributions

L.F.: Data collection, Surgery and patient management, Manuscript drafting. J.Y.: Manuscript editing, Manuscript critical revision. All authors have read and approved the final manuscript.

Conflicts of interest disclosure

The authors declare that they have no competing interests.

Guarantor

Jie Yu.

Research registration unique identifying number (UIN)

Not applicable.

Provenance and peer review

Not commissioned; externally peer reviewed.

Data availability statement

All data relevant to the study are included in the article.

Declaration of non-use of artificial intelligence

We hereby declare that no artificial intelligence (AI) tools, including but not limited to AI-based writing assistants, language models, data analysis tools, or content generation software, were used at any stage of this research project or during the preparation and development of this manuscript. All work presented is the original effort of the authors.