|Year : 2019 | Volume
| Issue : 3 | Page : 92-95
Obstructive tracheal neoplasm: Imaging and therapeutical features of pleomorphic adenoma
Badreeddine Alami1, Saïd Boujraf2, Mohamed Smahi3, Mounia Serraj4, Moulay Youssef Alaoui Lamrani5, Meryem Boubbou5, Mustapha Maaroufi5
1 Department of Biophysics and Clinical MRI Methods, Faculty of Medicine and Pharmacy, University of Fez; Department of Radiology and Clinical Imaging, University Hospital of Fez, Fez, Morocco
2 Department of Biophysics and Clinical MRI Methods, Faculty of Medicine and Pharmacy, University of Fez, Fez, Morocco
3 Department of Thoracic Surgery, University Hospital of Fez, Fez, Morocco
4 Department of Pneumology, University Hospital of Fez, Fez, Morocco
5 Department of Radiology, University Hospital of Fez, Fez, Morocco
|Date of Submission||22-Jun-2018|
|Date of Decision||18-Jul-2018|
|Date of Acceptance||16-Jan-2019|
|Date of Web Publication||17-Jun-2019|
Prof. Saïd Boujraf
Department of Biophysics and Clinical MRI Methods, Faculty of Medicine and Pharmacy, University of Fez, BP. 1893, KM 2.200, Sidi Hrazem Road, Fez 30000
Source of Support: None, Conflict of Interest: None
Primary tumor of the trachea is rare. Although most tumors in adults are malignant, various benign tumors might occur. However, pleomorphic adenoma of the trachea is extremely rare. So far, few cases have been reported in medical literature. We report a case of a 38-year-old man with 6 months history of dyspnea and wheezing; the asthma was the initial diagnosis formulated by his family doctor. However, the symptoms were not improved by asthma treatment. The patient was admitted to the emergency department for respiratory distress, and underwent nasal continuous positive airway pressure. Immediately, after an urgent chest computed tomography (CT) was done and revealed an obstructive tumor of the distal trachea which was homogeneous with a smooth and regular surface suggesting its benignity. The patient was operated urgently, the histological examination of the surgical specimen revealed pleomorphic adenoma. We present this case to inform colleagues that pleomorphic adenoma must be considered in the differential diagnosis of tracheal tumors, especially if we have an appearance on CT suggesting the benignity. Surgery is the treatment of choice of this tumor with the lowest recurrence probability.
Keywords: Adenoma, imaging, pleomorphic, tracheal
|How to cite this article:|
Alami B, Boujraf S, Smahi M, Serraj M, Lamrani MY, Boubbou M, Maaroufi M. Obstructive tracheal neoplasm: Imaging and therapeutical features of pleomorphic adenoma. Formos J Surg 2019;52:92-5
|How to cite this URL:|
Alami B, Boujraf S, Smahi M, Serraj M, Lamrani MY, Boubbou M, Maaroufi M. Obstructive tracheal neoplasm: Imaging and therapeutical features of pleomorphic adenoma. Formos J Surg [serial online] 2019 [cited 2020 May 31];52:92-5. Available from: http://www.e-fjs.org/text.asp?2019/52/3/92/260441
| Introduction|| |
Tracheal neoplasm is a rare pathological entity. Although most tumors in adults are malignant, various benign tumors might occur such as hamartomas and squamous cell papillomas, but pleomorphic adenoma of the trachea is an extremely rare benign tumor that arises from the mucous glands of the tracheobronchial tree,,, So far, few cases have been reported in medical literature. They were all localized in the upper third of the trachea except 12% which were reported to be in the lower third. The rarity and nonspecific symptoms of these benign primary tracheal tumors always leaded to misdiagnosis and delayed treatment, and also undefined the optimal treatment.
In this paper, we report a case of a pleomorphic adenoma arising in the lower third of trachea immediately above the carina. The tumor was surgically resected. We discuss the imaging features of this rare entity while correlating the pathological results to consider pleomorphic adenoma in the differential diagnosis of tracheal tumors.
| Patient and Methods|| |
The patient was a 38-year-old male with 6 months history of dyspnea, chronic cough, wheezing, and sputum production. The patient initial diagnosis was asthma performed by his family doctor. However, his symptoms were not relieved by the asthma treatment. The patient was admitted in the emergency department for marked limitations on the physical activity with fatigue and dyspnea occurring even during less than ordinary activity; he is comfortable only at rest (dyspnea of Class III according to the New York Heart Association classification).
The physical examination revealed respiratory distress with inspiratory and expiratory stridor. The remaining examination was inconspicuous. The patient underwent urgently nasal continuous positive airway pressure (CPAP). Chest contrast-enhanced computed tomography (CT) with multi-planar reconstruction was done in emergency and showed a well-defined endotracheal lesion measuring 1.5 cm × 1.2 cm × 1.8 cm, with moderate and homogenous enhancement. The lesion was localized in the distal trachea immediately above the carina. It was attached to the posterior wall of the trachea by a thin base; and was causing almost total obstruction of the lumen [Figure 1]. No other tracheobronchial lesion or extrinsic compression was noticed. The images showed homogeneous appearance with regular and smooth contours which is consistent with a benign tumor diagnosis. The treatment targeted to release the trachea obstruction. The patient underwent right thoracotomy with segmental resection and end-to-end anastomosis. The excised tumor exhibited a well-demarcated solid mass, measuring 2 cm in its longest axis. It was covered by intact mucosa without necrosis [Figure 2]. The histological examination of the surgical specimen revealed pleomorphic adenoma, the surgical margins of the resected trachea were free of tumor, so the resection was macroscopically and microscopically radical (R0). The postoperative course was uneventful, and the patient was asymptomatic with good health.
|Figure 1: Axial contrast-enhanced chest computed tomography in (a) with coronal and sagittal reconstructions in (b) and (c), respectively. The images are showing a well-defined endotracheal lesion measuring 1.5 cm × 1.2 cm × 1.8 cm, with moderate and homogenous enhancement pointed by white arrow. The mass is localized in the distal trachea immediately above the carina. This tumor configuration caused almost total obstruction of the lumen. The images revealed an iatrogenic pneumomediastinum related to mechanical ventilation pointed by red arrow|
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|Figure 2: The surgical piece contained an endotracheal polypoid mass. The global examination showed well-demarcated solid mass that was covered by intact mucosa without necrosis|
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| Discussion|| |
Benign tumors of the tracheobronchial tree are quite rare, they are accounting for <2% of all airway neoplasms. Most often, they arise from the mesenchymal tissue. The most common benign tumors are squamous cell papilloma, fibroma, hamartoma, and hemangioma. Although pleomorphic adenoma is the most common neoplasm of salivary glands, its occurrence in the trachea is extremely rare and is arising from the seromucous glands of the tracheobronchial tree. The age of diagnosis of this tumor is usually ranging between 35 and 74 years old. However, most reported cases occurred in the sixth and seventh decades., Indeed a case has been reported in an 8-year-old male. There is no gender predominance.,
Almost 50% of these tumors were localized in the upper third of the trachea and only 12% were reported to be localized in the lower third. In the present case, the mass ascended from the right posterior-lateral of the inner wall of the distal trachea just 6 mm above the carina.
In contrast with malignant tumors, most benign tracheal neoplasms, including pleomorphic adenoma are growing and evolving slowly. They are present with obstructive symptoms such as a cough, sputum, dyspnea, wheezing, and stridor signs. Thus, the diagnosis is often delayed, and the condition is usually mistreated as chronic obstructive pulmonary disease or bronchial asthma;,, as result, patients with such tumors are often undergoing prolonged treatment for obstructive lung disease. Thus, Aribas et al. reported the case of a 42-year-old woman who was treated for asthma for 2 years before a diagnosis of pleomorphic adenoma of the trachea; recently another case of misdiagnosed tracheal pleomorphic adenoma was reported by Kim et al., indeed the patient was receiving medication for bronchial asthma including bronchodilator inhalation therapy during the 12 months before a definitive diagnosis. This mimicking profile was also revealed in our patient with a 6-month history of dyspnea that underwent an asthma treatment before establishing the final diagnosis of pleomorphic adenoma. In this report, we aim to learn lessons that can help us to avoid the misdiagnosis and unnecessary treatment in the future. In fact, not all wheezing, stridor and dyspnea are related to common causes, such as asthma. Thus in case of failure of therapeutic response to bronchodilators and corticosteroids, we need to request radiological assessments.
Radiological investigations are important in diagnosing the patient at presentation. However, chest X-ray is not useful because tumors are rarely visualized. The thoracic CT has a capital diagnostic role with since being sensitive to up to 90% of cases. It also allows the evaluation of tumor characteristics, localization, and extension to distant and near structures, especially the carina.
The CT findings of reported cases of pleomorphic adenoma were an endotracheal polypoid mass with various degree of luminal occlusion. The lesions are circumscribed, homogeneous, with smooth surface.
Indeed in our case, CT imaging was useful for identifying the source of patient's obstructive symptoms, by showing a round lesion of 1.5 cm × 1.2 cm × 1.8 cm in the lower third of trachea just above the carina, with an obstruction rate of >80% of the tracheal lumen. The lesion was well demarcated with moderate and homogenous enhancement. The tumor's surface was smooth suggesting that this lesion was originated in the submucosa and sparing the overlying epithelium.
Flexible bronchoscopy performed under conscious sedation play a central role in diagnosis and treatment planning of tracheal tumors, including pleomorphic adenoma. This allows a precise assessment of tumor characteristics, including localization, extension, and the possibility of biopsy sampling.
The histological aspects of pleomorphic adenoma are similar to salivary gland neoplasms. Microscopic findings show trabecular or islands of cells with epithelial and mesenchymal differentiation, including myxoid, hyaline, chondroid, and osseous aspects.
Immunohistochemical assessments and staining may enhance the accuracy of the characteristics of the tumor; hence, it is the most accurate diagnostic tool of pleomorphic adenoma. The assessment would demonstrate positive myoepithelial cell components for cytokeratin, p63, and S100 protein.,
Because of their rarity and unpredictable oncologic behavior, there is no clear consensus regarding the management and prognosis of pleomorphic adenoma. Although they are few, most found reports have considered complete surgical excision as the treatment of choice for tracheal pleomorphic adenoma because of high incidences of recurrence,,, and the possibility of malignant transformation which has been reported in two cases. The procedure consists of segmental tracheal resection including the tumor with cuffs of normal tissue and end-to-end tracheal anastomosis.,, The adequate resection margins are not standardized in the literature given the rarity of the tumor. However, Park and Sung reported the case of a 59-year-old male with tracheal pleomorphic adenoma which underwent resection of four tracheal rings along with the tumor and end-to-end anastomosis.
Recently, a very few case reports have reported that this condition could also be treated by bronchoscopic removal with cold instruments, laser excision, cryotherapy, radiation, and an electrosurgical snare that can be applied for palliation when rapid recanalization or hemostasis is required. However, endoscopic resection is mainly used for tumors with small implantation base.
In terms of management for patients with benign tracheal tumor, the following conditions are considered as indications for surgical resection, rather than endoscopic treatment: when malignancy cannot be denied histologically, if accompanied with organized pneumonia or bronchodilation of the peripheral side beyond the tumor, tumors with extensive infiltration of >3 bronchial cartilage rings or invading beyond the tracheal wall. In addition, endoscopic treatment is not indicated in cases where it is not possible to confirm the condition of the peripheral bronchus beyond the point of tumor obstruction, or cases of fatal hemorrhage caused by perforation of the bronchial wall.,
In this case, we could not eliminate malignancy histologically, so we opted for surgical treatment with segmental resection including the tumor with cuffs of normal tissue and end-to-end anastomosis to avoid any recurrence.
| Conclusion|| |
Tracheal pleomorphic adenoma is a rare disease. It must be included in the differential diagnosis of patients with intractable asthma-like symptoms, especially if the response to treatment is inadequate. Thoracic CT and flexible bronchoscopy help in diagnostic confirmation and therapeutic planning. Surgery is the treatment of choice of this tumor with the lowest recurrence probability. However, endoscopic resection could also serve as a treatment option.
Finally, future studies with additional cases are needed to better define the diagnostic and therapeutic status of tracheal pleomorphic adenoma.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
The Patient consent form has been obtained from all patients.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]