J Thorac Cardiovasc Surg 2007;133:265-267
© 2007 The American Association for Thoracic Surgery
Primary pulmonary malignant schwannoma with extension to the tracheal carina
Mika Uchiyama, MDa,*,
Yoshie Shimoyama, MDb,
Noriyasu Usami, MDa,
Simon Ito, MDa,
Ayuko Yasuda, MDa,
Koji Kawaguchi, MDa,
Kohei Yokoi, MDa
a Division of Thoracic Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
b Department of Pathology and Clinical Laboratories, Nagoya University Hospital, Nagoya, Japan.
Received for publication July 21, 2006; accepted for publication September 5, 2006.
* Address for reprints: Mika Uchiyama, MD, Division of Thoracic Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. (Email: takepon{at}med.nagoya-u.ac.jp).
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Dr Uchiyama
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Primary pulmonary malignant schwannomas are extremely rare, and only 11 case reports of this tumor are available.1
All cases were treated with a relatively simple surgical procedure, such as pneumonectomy, lobectomy, or enucleation, but their clinicopathologic appearances have not been well clarified. We present a patient with this tumor, which originated in the right upper lobe of the lung and involved the mainstem bronchus and tracheal carina. For complete removal of the tumor, we performed right upper lobectomy of the lung using extended wedge resection of the tracheal carina, followed by anastomosis of the right intermediate trunk and the distal trachea.
Clinical Summary
A 57-year-old woman was admitted to our hospital with a 5-month history of worsening cough and dyspnea. There were no abnormal findings on physical and laboratory examinations. Chest x-ray films and computed tomographic scans revealed an apical right-sided large mass measuring 8.4 x 6.0 cm, which was adjacent to the superior vena cava, esophagus, and posterior wall of the distal trachea. The tumor also extended into the right mainstem bronchus as a polypoid lesion across the orifice of the right upper lobe (Figure 1). A bronchoscopic examination disclosed that the distal trachea was decompressed by the tumor from the right dorsal to the left side, and the right main bronchus was almost occluded by the polyp-shaped phyma. Computed tomography–guided percutaneous needle biopsy was applied, and the pathologic diagnosis was schwannoma.
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Figure 1. A, Chest computed tomographic scan showing an apical right-sided large mass, which was adjacent to the posterior wall of the distal trachea. B, Computed tomographic scan of the coronal view showing the tumor extended into the right mainstem bronchus as a polypoid lesion across the orifice of the right upper lobe.
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After achievement of general anesthesia with a double-lumen endotracheal tube, the operation was accomplished by means of a right posterolateral thoracotomy approach through the fifth intercostal space. The right upper lobe showed atelectasis with adhesion to the esophagus and superior vena cava, and the whole lobe was almost occupied with the tumor, which extended to the right main bronchus and tracheal carina. The superior pulmonary vein and superior trunk of the pulmonary artery were collapsed. The patient underwent right upper lobectomy of the lung with extended wedge resection of the right main bronchus and tracheal carina, including 3 cartilage rings of the trachea, followed by anastomosis of the right intermediate trunk and the distal trachea. The frozen sections of the surgical margins of the resected trachea and bronchus were negative for malignancy. The prepared fifth intercostal muscle flap was placed between the anastomosis and the pulmonary artery.
Pathologic examination demonstrated that the tumor, which measured 8.0 x 5.5 x 4.2 cm, occupied almost all the right upper lobe of the lung and invaded the right main bronchus and tracheal carina. Histologically, the tumor consisted of spindle cells, which were arranged randomly with hyperchromatic and atypical nuclei (Figure 2). There were few findings of nuclear palisading. Immunohistochemical study showed positive staining for S100 protein and negative staining for smooth muscle actin, CD34, neurofilament, and epithelial membrane antigen. There was 5% to 6% positive staining for MIB-1 (Ki-67), which indicates low-grade malignancy. Results from histologic and immunohistochemical studies yielded a definitive diagnosis of low-grade malignant schwannoma of the lung. The postoperative course was uneventful. A bronchoscopic examination was performed 7 months after the operation and revealed a well-patent anastomosis without recurrence.
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Figure 2. Histologically, the tumor consisted of spindle cells arranged randomly with hyperchromatic and atypical nuclei. (Hematoxylin-eosin stain, original magnification 200x.)
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Discussion
Malignant schwannomas account for approximately 5% to 10% of all soft tissue sarcomas. In its classic form a malignant schwannoma arises as a large fusiform or eccentric mass in a major nerve. Most malignant schwannomas are highly invasive and are associated with a low survival rate.2 Primary pulmonary malignant schwannomas are extremely rare, and only 11 surgical cases have been reported in the literature.1 Those patients were treated with pneumonectomy, lobectomy, or enucleation. One patient with a tumor 4 cm in diameter underwent a sleeve lobectomy. There were no reports of primary pulmonary malignant schwannoma with extension to the tracheal carina, as in our case. Prognoses of the patients with this tumor were generally poor. Two patients survived more than 20 years, whereas the others died of local recurrence or distant metastasis within 3 years.3,4 Because chemotherapy and radiotherapy have not been effective, the curative therapy for this disease is considered to be only radical resection.
Although carinal resection and reconstruction of the airways were used in the management of patients with malignant tumors involving the tracheal carina, the complications of anastomosis occurred frequently because of excessive tension, deficiency of blood flow at the site of anastomosis, or both.5 We successfully performed right upper lobectomy of the lung using extended wedge resection of the tracheal carina, and this technique was as easy and safe as the tracheobronchoplastic procedure. Furthermore, because of the nature of the tumor without diffuse infiltration, tumor-free surgical margins were obtained in this case.
This is the first case report of primary pulmonary malignant schwannoma involving the tracheal carina, which was successfully removed by using the extended bronchoplastic procedure.
References
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