Surgical management of giant solitary fibrous tumors of the pleura: Two case reports

Abstract

Introduction

Solitary fibrous tumor of the pleura (SFTP) is a rare primary tumor originating from mesenchymal cells located beneath the mesothelial-lined pleura. A special entity is the giant SFTP which presents unique challenges in surgical management.

Case presentation

Two cases of giant SFTPs in middle-aged patients are presented. Both patients presented with a recent worsening dyspnea and had imaging findings consistent with giant masses occupying the entire pleural cavity with a complete collapse of the homolateral lung and substantial contralateral deviation of heart and mediastinum. The pathological results of CT-guided transthoracic core needle biopsy was SFTP in both cases. Surgical resection was performed, and they both required two thoracotomies for complete tumor removal. Successful complete en bloc resection of the tumors was achieved with a total postoperative recovery. The first resected tumor was 30 × 20 cm and weighed 3500 g, the second was 33*x25 cm in size and weighed 4000 g. Both patients respiratory condition improved after the operation and no recurrence were noted in the follow-up.

Discussion

SFTPs are removed using various approaches: thoracotomy, sternotomy with the possibility of hemiclamshell extension, video-assisted thoracoscopic surgery (VATS), and robotic-assisted surgery. The challenge when operating giant SFTP (> 15 cm) is double: adhesions and compression to the lung tissue and surrounding mediastinal structures and the hyper vascular nature of the tumor. For giant SFTPs an open approach is preferable. Resection should be complete with negative margins due to the high risk of recurrence.

Conclusion

These cases emphasize the significance of personalized surgical strategies for managing giant SFTPs, providing valuable insights for clinicians addressing similar cases.

Highlights

• •SFTPs account for less than 5% of primary pleural tumors and in more than half of the cases the lesion shows no symptoms.
• •A special entity is the giant SFTP which presents unique challenges in surgical management given their considerable size and proximity to vital structures.
• •Effective management necessitates a multidisciplinary and individualized approach detailed in this article.

1. Introduction

Pleural tumors can be classified as diffuse or localized neoplasms [1]. Diffuse pleural mesotheliomas, originating from the mesothelial cells lining the pleura typically exhibit a diffuse pattern and are often highly malignant, frequently associated with asbestos exposure [2]. In contrast, solitary fibrous tumors of the pleura (SFTPs), a less prevalent form of localized tumor with only 900 cases reported from retrospective case reports and series, originate from the sub mesothelial mesenchymal layer [[1], [2], [3]]. While most SFTPs manifest as pedunculated masses with benign histologic features, approximately 12 % demonstrate malignant behavior, leading to death either from local recurrence or the development of metastatic disease [4]. Most SFTPs grow slowly and often remain asymptomatic, they rarely present with clinical manifestations such as cough, dyspnea, and chest pain which are more related to the tumor size [5]. SFTP is a rare tumor with an unpredictable prognosis and a unsystematic approach, particularly when considering surgical procedures and preoperative planning [6]. Contrast-enhanced computed tomography (CT) plays a crucial role in diagnosing the tumor and assessing its operability [3]. However, a definitive diagnosis relies on histopathological and immunohistochemical analysis. Complete surgical resection remains the treatment of choice [5]. A special entity is the giant SFTP (larger than 15 cm) which presents unique challenges in their surgical management. Herein, we report two rare cases of giant SFTPs operated at our thoracic surgery department emphasizing surgical management, and outcomes.

This case report has been reported in line with the SCARE Criteria [7].

2. Case presentation

2.1. Case 1

The first patient, a 59-year-old male, was complaining of acute left basal thoracic pain, cough, and a 4-week history of worsening breathlessness, especially lying down. He had comorbidities including diabetes mellitus and chronic bronchitis. Regular medications included metformin and inhaler salbutamol. He was a smoker and was usually independent with a performance status of zero. Clinical examination revealed diminished breath sounds with dullness to percussion in the left hemithorax. Chest X-ray showed a giant, homogeneous opacity in the left hemithorax. (Fig. 1 A).

Fig. 1.

A: Anteroposterior chest X-ray. Giant, homogeneous opacity in the left chest. B, C: A contrast-enhanced CT scan demonstrated a giant mass in the left hemithorax and the shift of blood vessels and mediastinum.

The CT scan revealed a well-vascularized pleural mass with heterogeneous enhancement, occupying the lower two-thirds of the left lung field. The tumor measured 24 × 17 × 28 cm and exhibited partial lung collapse and mediastinal shift (Fig. 1B, C).

2.2. Standard blood tests such as complete blood count was within normal limits

The patient's case was discussed in a multidisciplinary reunion, and a CT-guided transthoracic core needle biopsy of the mass before complete surgical resection was decided. The histopathologic examination revealed a solitary fibrous tumor with benign features.

Initially, a large left lateral thoracotomy through the 5th intercostal space was attempted. The 5th intercostal space representing the best approach for controlling the hilum and its vessels. Intraoperative findings showed that the mass was adherent to the diaphragm, mediastinum, and lingula, with moderate pleural effusion. The strong adhesions and the large tumor size posed challenges in complete resection. A second low lateral thoracotomy through the 8th intercostal space was performed enabling adhesiolysis, ligature of the main vascular pedicles of the tumor, and en bloc resection of the tumor involving a lingulectomy for ensuring negative margins (Fig. 2).

Fig. 2.

A: Intraoperative photograph showing the pedicle (*) of a large solitary fibrous tumor of the pleura. B: large left lateral thoracotomy through the 5th intercostal space and low lateral thoracotomy through the 8th intercostal.

There were no anesthetic complications during the procedure.

The post-operative course was simple (Fig. 3A).

Fig. 3.

A: Post-operative picture of the thorax showing the two lateral thoracotomies and chest tube drainage. B: The surgical specimen measuring 30 × 20*17 cm in size and encapsulated. C: Tumor proliferation composed of spindle-shaped cells within a richly vascularized stroma (100× magnification). The tumor cells are oval or spindle-shaped with scanty cytoplasm and vesicular, nucleated nuclei (400× magnification).

Macroscopically, the well-circumscribed, encapsulated resected tumor was 30 × 20 cm with extensive vessels and weighed 3500 g in the fresh state (Fig. 3B).

Histopathologic examination showed spindle-shaped tumor cells mixed with collagen bands and were consistent with benign SFTP (Fig. 3C).

The recovery was uneventful, and the patient was discharged on day 6 with no respiratory symptoms. Satisfactory radiographic control was achieved at 2 months post-surgery and there was no evidence of recurrence or metastasis at 1 year follow-up.

2.3. Case 2

The second patient is a 42-year-old female presented with a 4-week history of worsening breathlessness. She had no comorbidities, had never smoked, and denied exposure to asbestos, radon gas, and other occupational exposures. Clinical examination revealed diminished breath sounds with dullness to percussion in the right hemithorax.

CT scan revealed a giant tissular mass of 28 × 19 * 30 cm in the right hemithorax which extended from the right apex downward to the level of right kidney with downward compression of the diaphragm and complete atelectasis of the right lung (Fig. 4).

Fig. 4.

A, B, C: a well-vascularized pleural mass with heterogeneous enhancement, filling the right hemithorax, leading to almost total atelectasis of the lung, mediastinal shift, and compression of the surrounding blood vessels. The tumor measured 28 × 19 * 30 cm.

This case was also discussed in a multidisciplinary reunion; a CT-guided transthoracic core needle biopsy was performed, and the histopathologic examination revealed a solitary fibrous tumor.

We decided from the start on two posterolateral thoracotomies for this patient to ensure better exposure and the ability to enlarge our incision if needed, careful adhesiolysis from the diaphragm, and mediastinal fat and en bloc complete extraction of the mass with negative margins (Fig. 5A, B).

Fig. 5.

A: Posterolateral thoracotomy through the 5th intercostal space with enlargement of the incision for better exposure. B: En bloc extraction of the tumor with the picture showing the combination of two posterolateral thoracotomies through the 5th and 8th intercostal spaces. C, D: The surgical specimen measuring 33 × 25 cm in size, encapsulated, and weighed 4000 g. E: Radiography at 1-week post-surgery showing a complete expansion of the right lung.

Once the tumor was successfully removed, the patient's blood pressure dropped immediately due to the acute mediastinal shift, re-expansion of the right lung and fluid filling permitted the stabilization of the patient's hemodynamics.

After surgery the patient was transferred to the intensive care unit and was successfully extubated the same day.

Macroscopically, the well-circumscribed, encapsulated resected tumor was 33 × 25 cm and weighed 4000 g in the fresh state (Fig. 5C, D).

Histopathologic examination showed spindle-shaped tumor cells mixed with collagen bands and were consistent with benign SFTP.

The patient was discharged on postoperative day 7 after full recovery. Post-operative radiographic control was satisfactory (Fig. 5E).

There was no evidence of recurrence at 6 months follow-up.

3. Discussion

Solitary fibrous tumor (SFT) is uncommon with an incidence of 1 new case/million people/year [8]. It is a slowly developing mesenchymal tumor abundant in blood vessels originating from dendritic stromal cells expressing the CD34 antigen, with no gender predilection [9]. Typically diagnosed in individuals aged 50–70 years, SFT rarely occurs in younger patients [10]. The patient described in the second case was relatively young, at 42 years of age when diagnosed. SFTPs account for <5 % of primary pleural tumors and in more than half of the cases the lesion shows no symptoms [8]. Typically, these tumors are discovered incidentally during routine chest radiographs [8]. Symptoms tend to be more prevalent in larger lesions, leading to cough, chest pain, dyspnea, and rarely hypoglycemia. An analysis revealed that 46 % of pleural SFTPs presenting with hypoglycemia were malignant [10]. Our patients presented non-specific symptoms provoked by the size of the tumor. Making a preoperative diagnosis of SFTP based on radiological imaging can pose challenges, and distinguishing between malignant and benign is difficult when based on the sole imagery. Effective management and prognosis of SFT differs from that of its malignant counterparts, highlighting the critical importance of accurate diagnosis. CT-guided transthoracic core needle biopsy may help but has a low diagnostic sensitivity [11]. The presence of NAB2-STAT6 gene fusion and its immunohistochemical expression are consistently detected in these tumors. Immunohistochemistry represents the most sensitive and specific method for diagnosing SFTP, offering practical and cost-effective advantages [12]. In our cases, a CT-guided biopsy oriented towards the correct diagnosis. Benign SFTPs are usually small and pedunculated, whereas malignant SFTPs typically exceed 10 cm in diameter [6]. A tumor with a diameter larger than 15 cm or occupying >40 % of the hemithorax is classified as a giant SFTP [6]. For our patients, the tumors had been growing for many years, consistent with the benign tumor growth pattern. Surgical resection is the main treatment of SFTP, yet achieving complete en bloc resection can pose challenges due to its hyper vascular nature and significant adhesions. The utilization of Video-assisted thoracoscopic surgery (VATS) or robotic techniques may be appropriate for specific tumors, offering advantages such as decreased postoperative pain, less impact on respiratory function, and improved cosmetic outcomes compared to open surgery. Nevertheless, converting to an open technique is strongly advised if achieving adequate margin clearance proves challenging with these methods [6]. VATS could be used for lesions <5 cm, small pedunculated, at the periphery of the lung or in addition of an initial thoracotomy. It is important to consider the best surgical approach beforehand. There is no universally accepted method for such scenarios, with documented cases revealing customized incisions tailored to the tumor's size and precise location. In our cases, we conducted two thoracotomies at two different levels. The initial thoracotomy site was at the 5th intercostal space; lateral thoracotomy in the first case and posterolateral thoracotomy for the second, which allows entry into the pleural space directly over the pulmonary hilum. The fifth space is approximately in the center of the chest cavity offering better access, above and below, to the entire thoracic field filled by the tumor. We recommend a posterolateral thoracotomy for better exposure and dissection and the ability to enlarge the incision if needed. Subsequently, in both instances, an additional small incision was made at the 8th intercostal space to facilitate adhesiolysis with the diaphragm and pushing the tumor to extract it via the fifth space. These cases highlight the effectiveness of tailored surgical approaches in managing giant SFTPs and provide valuable insights for clinicians managing similar cases. Limitations include the retrospective nature of the case reports and the absence of long-term follow-up data. Furthermore, advancements in molecular biomarkers and other novel technologies offer promising avenues for enhancing diagnostic accuracy and guiding personalized treatment strategies in the management of giant SFTs of the pleura but they require costly equipment and highly skilled personnel, thereby limiting their practicality and feasibility in resource-constrained laboratories of developing countries [12].

4. Conclusion

SFTP is a rare condition often lacking evident clinical symptoms. Giant SFTs of the pleura pose a great surgical challenge given their considerable size and proximity to vital structures. Effective management necessitates a multidisciplinary and individualized approach, including preoperative imaging, histological confirmation, and precise surgical planning to ensure complete resection while preserving lung function and minimizing morbidity. This case highlights the significance of early diagnosis, comprehensive preoperative assessment, and expert surgical technique in achieving favorable outcomes for patients with giant SFTs of the pleura. Furthermore, advancements in molecular biomarkers and other novel technologies offer promising avenues for enhancing diagnostic accuracy and guiding personalized treatment and follow-up strategies in the management of SFTs of the pleura.

Consent

Written informed consent was obtained from the patients for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Ethics clearance was not necessary. It is a case report describing a rare clinical presentation. Institution: Department of Thoracic Surgery, Abderrahmen Mami Hospital, Ariana, Tunisia; Faculty of Medicine of Tunisia

Funding

N/A.

Author contribution

Chaieb Wassim: conceived the work, contributed to writing, reviewing and finalization of the manuscript.

Bouassida Imen: contributed to reviewing and finalization of the manuscript.

Abdelkabir Amina: contributed to reviewing the manuscript.

Abdennadher Mahdi: contributed to reviewing the manuscript.

Zribi Hazem: approval of the final version.

Marghli Adel: approval of the final version.

Guarantor

Chaieb Wassim

Research registration number

It is not a first in Man. It is a case report about a rare clinical presentation.

Institution: Department of Thoracic Surgery, Abderrahmen Mami Hospital, Ariana, Tunisia; Faculty of Medicine of Tunisia

Conflict of interest statement

N/A.