Abstract
Introduction
Schwannomas are rare, typically benign, solitary and encapsulated lesions. These benign neoplasms originating from Schwann cells of the peripheral nerve sheath represent less than 1% of all primary retroperitoneal tumors [4]. Radical resection without disrupting the integrity of the capsule is the mainstay of treatment for primary retroperitoneal schwannomas, otherwise recurrence has been reported in 5-10% of cases [5].
In this article, a simultaneous excision of intrathoracic solitary fibrous tumor and retroperitoneal schwannoma using the robot-assisted system.
Case Presentation
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In the first stage, four robotic trocars were placed after the patient was positioned the left flank. After docking, the robotic arms were connected to the trocars and the instruments were placed in the abdomen. The Toldt line was incised and the intestinal structures were medialized and removed from the operation line. Gerato's fascia and kidney lower pole were observed. A solid mass with a size of 2.5 × 2 cm was seen in the Gerato’s facia, separate from the kidney tissue. Total excision was performed with the appropriate surgical margins and without deterioration of capsule integrity. Afterwards, the patient was placed in the left lateral decubitus position, and a total of four port incisions were made in the right hemithorax, three for robotic arms and one for the assistant surgeon (Figure 2). Robotic arms were installed. On exploration, a mass approximately 4 cm in diameter with a paravertebral location was detected at the T8 level (Figure 3). The mass was completely excised (Figure 4). Total operation time was 280 minutes, and the total blood loss was 100 ml in both surgery. The patient was mobilized immediately after the operation. After an uneventful postoperative period the patient was discharged two days after surgery.
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Figure 2. Placement of thorocars in robot-assisted thoracic Surgery
(a), postoperative view of port and drain locations (b).
Figure 3. Intrathoracic view of the thoracic mass.
Figure 4. Schematic view of both masses.
In the histopathological examination, the mass excised
from the retroperitoneal region measured 2.5 × 2 × 2 cm
and was evaluated as a schwannoma. Immunohistochemically,
S-100 was positive and CD34 was negative. The
intrathoracic excised mass measured 4.5 × 3.5 × 3 cm in
diameters and was reported as a solitary fibrous tumor. Immunohistochemical
examination of SFT revealed CD34
(+), EMA and S-100 (-). No recurrence was observed at
the 3-years follow-up. Written informed consent was obtained
from the patient for the publication of her data.
Discussion
In a review article including ten studies, the recurrence rate of benign solitary fibrous tumors was reported as 3% [7]. In our case, no recurrence was detected at three-year follow-up.
The minimally invasive approach has become the golden standard in many surgical branches, including thoracic surgery. Ghanim et al emphasized that videoassisted thoracic surgery (VATS) is the most commonly used minimally invasive technique in the treatment of small sized intrathoracic SFTs, compared to open surgery [8]. Robot-assisted surgery is also an important minimally invasive surgical technique. The advantages of this system are that it allows three-dimensional (3D) imaging, the surgeon's tremor is not reflected in the robotic arm movements, and simultaneously it provides more freedom of movement with multi-jointed robotic arms. Similar morbidity rates and length of hospitalization are observed by robot-assisted surgery compared to VATS in the resection of mediastinal tumors and cysts [9]. No complications were observed after robot-assisted surgery in our patient.
Schwannoma originating from Schwann cells of peripheral or cranial nerves is encountered in the retroperitoneal space in only 0.5% of cases [10]. The majority of patients are often asymptomatic or may present with nonspecific and vague symptoms, as in our case, and it is detected incidentally. It is difficult to make a definitive diagnosis in the preoperative period, especially due to it is rare occurrence in the retroperitoneal region. Macroscopically, retroperitoneal schwannomas are encapsulated and well-circumscribed tumors. In this case, the excised material was also encapsulated, shiny in appearance and orange in color on sections. In the immunohistochemical examination, the generally accepted S-100 positivity was also detected in our case.
The prognosis of schwannomas excised from the retroperitoneal region is generally satisfactory and recurrence is seen in 5-10% of patients probably due to inadequate excision [11]. In our case, no recurrence was observed during the 3-years follow-up period.
Robot-assisted surgery allows easier dissection, vessel ligation and suturing when compared to laparoscopic surgery. Consequently, a significant reduction in the intraoperative blood loss was observed with the robotic approach in dissection of deep tissues such as the retroperitoneal region. We did not encounter any bleeding after the simultaneous surgery we performed. As reported in some studies, the most important disadvantages of robotic surgery are longer mean operation time and higher cost compared to laparoscopy [12].
Despite the widespread use of robot-assisted surgery, especially in recent years, and oncological surgeries being increasingly performed with this technique, we have not encountered a case of simultaneous excision of intrathoracic and retroperitoneal masses with this technique in the literature. Principally, in these cases, two-stage surgery (the first treatment is for the more aggressive lesion) is performed as a treatment plan. The advantage of treating two neoplasms simultaneously is to avoid delaying treatment of the second tumor, especially in young patients. Possible problems can be listed when the treatment is performed in two stages include delay in excision of other masses due to waiting for the postoperative healing phase after the first surgery and intermittent anesthesia. This results, in turn, leads to an increase in cost and in the duration of hospitalization.
In conclusion, simultaneous minimally invasive surgery for small masses in the posterior mediastinum and retroperitoneal region may be appropriate in selected patients. Robotic-assisted surgery can be an alternative minimally invasive technique to VATS because of its technical superiorities. The only disadvantage of both robotic assisted surgery and simultaneous operation is prolonged operation time.
Declaration of conficting interests
The authors declared no conficts of interest with respect
to the authorship and/or publication of this article.
Funding
The authors received no financial support.
Authors’ contributions
SM;TÇ;ÖS;ÖÇ;MŞ: conceived and designed the current
case report, co-wrote the paper, collected the clinical
data. The authors discussed the case under the literature
data together and constituted the final manuscript.
Reference
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