AJR ARRS: Your Link to CME
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chong, S.
Right arrow Articles by Han, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chong, S.
Right arrow Articles by Han, J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?
DOI:10.2214/AJR.04.1711
AJR 2006; 186:220-224
© American Roentgen Ray Society

Clinical Observations

Tracheal Metastasis of Lung Cancer: CT Findings in Six Patients

Semin Chong1, Tae Sung Kim1 and Joungho Han2

1 Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
2 Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.

Received November 5, 2004; accepted after revision January 4, 2005.

 
Supported by grant R11-2002-103 from the Korea Science & Engineering Foundation.

Address correspondence to T. S. Kim (tskim.kim{at}samsung.com).


Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
OBJECTIVE. Our objective was to assess CT findings of tracheal metastasis of lung cancer.

CONCLUSION. Tracheal metastasis of primary non-small cell lung cancer manifested as an endotracheal nodule or eccentric wall thickening of the trachea, showing contrast enhancement with a predilection for the upper trachea on CT. During postoperative evaluation of patients with surgically resected lung cancer, the possibility of tracheal metastasis of lung cancer should be suggested when an endotracheal nodule or eccentric wall thickening is present on CT.

Keywords: airway • cancer • CT • lung diseases


Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Tracheal metastasis of primary lung cancer is extremely rare, although direct tracheal involvement by primary lung cancer is often seen and classified as T4 lung cancer [1]. Tracheal metastases from nonpulmonary malignancies such as breast cancer, colorectal carcinoma, renal carcinoma, and melanoma have been reported [2-7]. To our knowledge, however, only one case of tracheal metastasis from primary lung cancer has been reported in the Japanese-language literature [8]. To our knowledge, it has not yet been reported in the English-language literature. We retrospectively assessed chest CT scans obtained in six patients with histopathologically proven tracheal metastasis from primary lung cancer.


Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Between November 1995 and September 2004, six patients (all men; age range, 53-68 years; mean age, 61 years) with histopathologically proven tracheal metastasis after surgical resection of primary lung cancer were identified from the file archives of the department of pathology at our institute. Approval from the institutional review board was not needed for review of pathologic reports and radiologic images in our institute. We retrospectively reviewed the patients' clinical, CT, and histopathologic findings.

Clinical features and histologic subtypes of the previously resected lung cancer in the patients are summarized in Table 1. The location of the initial primary lung cancers was the right lower lobe (n = 3), left upper lobe (n = 2), or left lower lobe (n =1). The cell type of the primary lung cancers was squamous cell carcinoma (n = 5) or adenocarcinoma (n = 1). All patients underwent lobectomy (n =4) or pneumonectomy (n = 2) for primary lung cancer, and their pathologic staging was IA (n = 1), IB (n = 2), IIB (n = 1), or IIIA (n = 2). After surgery, all six patients were followed up with a chest CT scan at 3-6 months for early detection of possible tumor recurrence or pulmonary metastasis. At the time of diagnosis of tracheal metastasis, all patients were asymptomatic and had no extrathoracic metastatic lesions.


View this table:
[in this window]
[in a new window]

  		TABLE 1: Clinical Features and CT Findings of Six Patients with Tracheal Metastasis of Surgically Resected Non–Small Cell Lung Cancer

 

Nonenhanced and contrast-enhanced helical chest CT images were obtained in all patients using a helical CT scanner (HiSpeed Advantage, GE Healthcare). The parameters of the helical chest CT examination were a 5-mm collimation and a 10-mm/sec table feed. Contrast-enhanced chest CT scans were obtained after injection of 30 g of iodinated contrast medium (100 mL of iopamidol [Iopamiron 300, Bracco]) at a rate of 3 mL/sec with a power injector (OP 100, Medrad).

Chest CT scans were analyzed retrospectively and jointly by two radiologists with 7 and 2 years of experience, respectively, in chest radiology. The decisions on the CT findings were reached by consensus. Chest CT scans were assessed specifically for the location and pattern of tracheal abnormalities, degree of contrast enhancement, and presence or absence of disruption of the cartilaginous rings and mediastinal or hilar lymphadenopathy. We classified the location of tracheal abnormalities into the upper or lower trachea from a horizontal line drawn tangential to the upper margin of the aortic arch; right or left side of the tracheal wall; and anterior, posterior, or lateral portion based on the cross-sectional scan. We classified the pattern of tracheal abnormalities into an endotracheal nodule or eccentric wall thickening with endo- and exophytic tumor growth. We measured the longest diameter of the endotracheal nodule or the maximum thickness of tracheal wall thickening. Contrast enhancement was regarded as significant when a net enhancement of more than 10 H between pre- and postcontrast images at the same level was present.

All six patients underwent bronchoscopic biopsy for the tracheal lesion. One of them underwent segmental resection and anastomosis of the trachea. The histopathologic findings of the specimens obtained from bronchoscopic biopsy or surgical resection were evaluated by a pathologist with 9 years of experience. We defined tracheal metastasis from primary lung cancer as tracheal lesions histopathologically identical to the previous primary lung cancer.

We calculated the recurrence interval, which was defined as the time interval from the resection of the primary lung cancer to the detection of the tracheal abnormality on follow-up CT, and assessed the overall incidence of tracheal metastasis in surgically resected primary lung cancers. We also reviewed patients' treatment and clinical outcome.


Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
CT findings of tracheal metastasis in the six patients are summarized in Table 1. All six patients showed an endotracheal nodule (n = 4) (Figs. 1A, 1B, and 2A) or eccentric tracheal wall thickening with endo- and exophytic tumor growth (n = 2) (Fig. 3A) on CT. The location of the endotracheal nodule or eccentric wall thickening was the upper (n =4) or lower (n = 2) trachea based on the upper margin of the aortic arch. The tracheal lesion was located in the right (n = 1), midline (n = 1), or left (n =4) side of the trachea, which was the anterolateral (n =3), anterior (n = 1), or posterolateral (n = 2) portion of the trachea. The longest diameters of the endotracheal nodule or the maximum thickness of eccentric wall thickening were 6-27 mm (mean, 14.3 ± 7.5 [SD] mm). We assessed the degree of contrast enhancement in five patients, which showed 20-30 H (mean, 24.6 ± 4.6 H) of net enhancement. In the remaining patient (patient 4), we could not obtain the value of net enhancement because a 6-mm endotracheal nodule was not covered in a precontrast thin-section (1-mm collimation) scan because of a scanning gap. Partial disruption of a cartilaginous ring by the tracheal tumor was noted in five patients. Mediastinal (n = 3) or hilar (n = 1) lymph nodes (7 or 8 mm) were seen in three patients. Among them, a 7-mm right upper paratracheal lymph node (patient 3) was histopathologically proven to be a metastatic lymph node from squamous cell carcinoma at surgery (tracheal resection and anastomosis). One patient (patient 4) had a simultaneous pulmonary metastasis with an 11-mm nodule in the left lower lobe.



View larger version (61K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 1A —53-year-old man who had undergone right middle and lower lobectomy for squamous cell carcinoma 52 months earlier (patient 3 in Table 1). Chest CT scan shows 10-mm endotracheal nodule (arrow) in right lower posterolateral portion of trachea.

 


View larger version (116K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 1B —53-year-old man who had undergone right middle and lower lobectomy for squamous cell carcinoma 52 months earlier (patient 3 in Table 1). Photomicrograph of transaxial section of gross specimen obtained from tracheal resection and anastomosis shows endotracheal polypoid nodule (arrows) with transmural growth. (H and E, x1)

 


View larger version (111K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 2A —60-year-old man who had undergone left upper lobectomy for adenocarcinoma 26 months earlier (patient 1). Chest CT scan shows 13-mm endotracheal nodule (arrow) in left upper posterolateral portion of trachea.

 


View larger version (75K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 3A —68-year-old man who had undergone left upper lobectomy for squamous cell carcinoma 17 months earlier (patient 2). Chest CT scan shows eccentric thickening (arrow) of anterior midline portion of tracheal wall.

 
On histopathologic examination of tracheal biopsy specimens obtained from all patients, the cell type of the tracheal lesion was squamous cell carcinoma (n = 5) (Figs. 1C and 3B) or adenocarcinoma (n = 1) (Fig. 2B). All tracheal tumor cells were identical to the previously resected primary lung cancers and were seen in the submucosal layer. As described above, one of four lymph nodes was surgically resected and proved to be a metastasis from the previously resected squamous cell carcinoma.



View larger version (163K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 1C —53-year-old man who had undergone right middle and lower lobectomy for squamous cell carcinoma 52 months earlier (patient 3 in Table 1). Photomicrograph of pathologic specimen reveals well-differentiated squamous cell carcinoma showing densely eosinophilic foci (arrows) corresponding to keratin pearl formation. (H and E, x200)

 


View larger version (161K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 3B —68-year-old man who had undergone left upper lobectomy for squamous cell carcinoma 17 months earlier (patient 2). Photomicrograph of histopathologic specimen obtained from bronchoscopic biopsy shows nest of squamous cell carcinoma (arrowheads) in submucosal layer. Note normal overlying respiratory mucosa (arrows). (H and E, x100)

 


View larger version (151K):
[in this window]
[in a new window]
[as a PowerPoint slide]
  		Fig. 2B —60-year-old man who had undergone left upper lobectomy for adenocarcinoma 26 months earlier (patient 1). Photomicrograph of histopathologic specimen obtained from bronchoscopic biopsy shows adenocarcinoma forming acini (arrow) and micropapilla (arrowheads). (H and E, x200)

 
In our series, the overall incidence of tracheal metastasis was 0.44% (6/1,372) in the surgically resected non-small cell lung cancers during the same period in our institute of 8 years 10 months: 0.77% (5/647) in squamous cell carcinomas and 0.18% (1/552) in adenocarcinomas. The recurrence interval was 8-52 months (mean, 25.8 ± 17.4 months) after their initial operation.

Shortly after the diagnosis of newly developed tracheal metastasis, four patients underwent radiation therapy and one patient was treated with chemotherapy. The remaining patient (Figs. 1A, 1B, and 1C) underwent tracheal segmental resection and anastomosis. All patients showed complete remission of the tracheal metastasis and, to date or as of the last follow-up examination, have not had a known recurrence. All patients were alive for the 17- to 68-month follow-up period (mean, 35 ± 21 months) after the previous surgical resection of the primary lung cancer. However, five of six patients showed newly developed metastatic lesions (metastatic mediastinal lymph nodes, stump recurrence, or lung-to-lung metastasis) on follow-up CT scans. After subsequent radiation therapy or chemotherapy, they have been in partial response (n = 3) or progressive disease (n = 2) (Table 1).


Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
To our knowledge, the incidence of endotracheal or endobronchial metastasis of primary lung cancer has not been reported in the literature. However, the incidence of endotracheal or endobronchial metastasis of nonpulmonary malignancies is known to vary, ranging from approximately 2% to 50%, according to how they are defined [9-14]. In our study, the overall incidence of tracheal metastasis was 0.44% (6/1,372) in surgically resected non-small cell lung cancer (0.77% in squamous cell carcinomas and 0.18% in adenocarcinomas), and the incidence of tracheal metastasis was lower in primary lung cancers than in nonpulmonary malignancies.

The symptoms associated with endotracheal and endobronchial metastases regardless of its primary site are similar to those associated with primary endotracheal and endobronchial tumors. Hemoptysis with coughing is the most common symptom, with an incidence of 41-62% reported [9, 15]. In our study, all patients with tracheal metastasis were free of symptoms despite the endotracheal nodule or eccentric wall thickening shown on CT. The small endotracheal nodule or mild wall thickening did not result in significant airway narrowing in our series. The periodic postoperative follow-up CT examinations that were performed may have detected the tracheal metastasis at a subclinical stage—that is, before the onset of clinical symptoms and signs.

In primary tracheal tumors, the most frequent site is the lower one third of the trachea [16]. However, tracheal metastasis of non-small cell lung cancer in our series showed a predilection for the upper trachea (n = 4) in location, although the study population was small (n = 6). In our series, the site of tracheal metastasis was ipsilateral to that of the primary tumor in three patients, contralateral in two patients, and midline in one. Therefore, there seemed to be no correlation in laterality between the location of the primary tumor and the site of tracheal metastasis.

In a clinicopathologic study of endotracheal and endobronchial metastases, Kiryu et al. [17] proposed four types of developmental modes of endotracheal and endobronchial metastases in a morphologic way: type 1, direct metastasis to the bronchus; type 2, bronchial invasion by a parenchymal lesion; type 3, bronchial invasion by mediastinal or hilar lymph node metastasis; and type 4, a peripheral lesion extending along the proximal bronchus. We suggest that the developmental mode of endotracheal metastasis in our series corresponded to type 1 metastasis (direct metastasis). In a study of endobronchial metastasis, Heitmiller et al. [14] proposed that the metastatic tumor migrated along the lymphatics with subsequent egress into the submucosal space. In our study, all tracheal tumor cells involved the submucosal layer, and some tracheal tumor cells were found within the submucosal lymphatic vessels presenting as tumor emboli (patient 1). These histologic findings support the assertion that tracheal tumor cells may originate from the primary site via submucosal lymphatic or blood vessels rather than from carcinoma in situ by field cancerization theory [18], which was proposed to explain the development of multiple primary tumors and locally recurrent cancer. According to the theory, the persistence of abnormal tissue after surgery (a preneoplastic field with genetically altered cells) may explain the development of secondary primary tumors by epithelial malignant transformation in the normal mucosa [18]. In our cases, however, tumor cells were located only in the submucosal layer without invasion of mucosal epithelium. Therefore, our cases should be considered tracheal metastasis rather than a secondary primary tracheal tumor.

Endotracheal and endobronchial metastases from nonpulmonary malignancies have been reported to progress relatively slowly [10]. In endotracheal and endobronchial metastases from nonpulmonary malignancies, the reported median recurrence intervals were 50.4-65.3 months [10, 11, 17]. In our study, the mean recurrence interval was 25.8 months. We suggest that our shorter mean recurrence interval may have resulted from early detection of subclinical tracheal metastasis during periodic postoperative follow-up examinations.

When an endotracheal nodule is present on a postoperative CT scan, an endotracheal tumor needs to be distinguished from an endotracheal phlegm termed "mucoid pseudotumor," which can be confirmed by its disappearance on a subsequent study or upward migration of the mucous plug after an episode of vigorous coughing [19]. In the present study, we found frequent disruption of the cartilaginous rings (n =5) and contrast enhancement (n = 5) of the tracheal lesions. To distinguish an endotracheal tumor from an endotracheal phlegm, therefore, we suggest an evaluation of the imaging criteria— that is, the presence or absence of disrupted cartilaginous rings, high-resolution CT after contrast enhancement, and possible CT maneuvers (repeated or coughing after CT).

Our study has some limitations. The major limitation is that the sample size was small because of the very low incidence of tracheal metastasis from primary lung cancer. Second, the bronchoscopic biopsy specimens may not be satisfactory to differentiate between primary and secondary tracheal malignancies. Salud et al. [11] suggested that there is no absolute histopathologic criteria to differentiate between primary and secondary tumors, although knowledge of the clinical situation and results from immunohistochemical techniques can be useful. Therefore, most study groups, including our study group, have defined endotracheal or endobronchial metastasis as the lesions histopathologically identical to the primary tumors previously documented [17].

In conclusion, tracheal metastasis of non-small cell lung cancer manifested as an endotracheal nodule or eccentric thickening of the tracheal wall, showing contrast enhancement with a predilection for the upper trachea on CT. During postoperative evaluation of patients with surgically resected lung cancer, the possibility of tracheal metastasis of lung cancer should be suggested when an endotracheal nodule or eccentric thickening of the tracheal wall is seen on CT.


References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Kameyama K, Huang CL, Liu D, et al. Problems related to TNM staging: patients with stage III non-small cell lung cancer. J Thorac Cardiovasc Surg 2002;124 : 503-510[Abstract/Free Full Text]
  2. DeBeer RA, Garcia RL, Alexander SC. Endobronchial metastasis from cancer of the breast. Chest 1978;73 : 94-96[Abstract/Free Full Text]
  3. Albertini RE, Ekberg NL. Endobronchial metastasis in breast cancer. Thorax 1980; 35:435 -440[Abstract/Free Full Text]
  4. Watanabe S, Oda M, Ohta Y, Watanabe G. Endotracheal metastasis of rectal cancer. Eur J Cardiothorac Surg2002; 21:924[Free Full Text]
  5. MacMahon H, O'Connell DJ, Cimochowski GE. Pedunculated endotracheal metastasis. AJR 1978;131 : 713-714[Medline]
  6. Koyi H, Branden E. Intratracheal metastasis from malignant melanoma. J Eur Acad Dermatol Venereol2000; 14:407 -408[CrossRef][Medline]
  7. Fraser RS, Muller NL, Colman N, Pare PD. Diagnosis of diseases of the chest, 4th ed. Philadelphia, PA: WB Saunders,1999 : 1381-1417
  8. Sakai T, Ikeda T, Kikuchi K, Maruyama M, Fukayama M, Kaseda S. A case of tracheal metastasis of pulmonary cancer [in Japanese]. Nippon Kyobu Geka Gakkai Zasshi 1986;34 : 1178-1181[Medline]
  9. Braman SS, Whitcomb ME. Endobronchial metastasis. Arch Intern Med 1975; 135:543 -547[Abstract/Free Full Text]
  10. Baumgartner WA, Mark JB. Metastatic malignancies from distant sites to the tracheobronchial tree. J Thorac Cardiovasc Surg1980; 79:499 -503[Medline]
  11. Salud A, Porcel JM, Rovirosa A, Bellmunt J. Endobronchial metastatic disease: analysis of 32 cases. J Surg Oncol1996; 62:249 -252[CrossRef][Medline]
  12. Katsimbri PP, Bamias AT, Froudarakis ME, Peponis IA, Constantopoulos SH, Pavlidis NA. Endobronchial metastases secondary to solid tumors: report of eight cases and review of the literature. Lung Cancer 2000; 28:163 -170[CrossRef][Medline]
  13. King TE Jr, Neff TA, Ziporin P. Endobronchial metastasis from the uterine cervix: presentation as primary lung abscess. JAMA 1979; 242:1651 -1652[Abstract/Free Full Text]
  14. Heitmiller RF, Marasco WJ, Hruban RH, Marsh BR. Endobronchial metastasis. J Thorac Cardiovasc Surg1993; 106:537 -542[Abstract]
  15. Fitzgerald RH Jr. Endobronchial metastases. South Med J 1977; 70:440 -441[Medline]
  16. Weber AL, Grillo HC. Tracheal tumors: a radiological, clinical, and pathological evaluation of 84 cases. Radiol Clin North Am 1978; 16:227 -246[Medline]
  17. Kiryu T, Hoshi H, Matsui E, et al. Endotracheal/endobronchial metastases: clinicopathologic study with special reference to developmental modes. Chest 2001;119 : 768-775[Abstract/Free Full Text]
  18. Braakhuis BJ, Tabor MP, Kummer JA, Leemans CR, Brakenhoff RH. A genetic explanation of Slaughter's concept of field cancerization: evidence and clinical implications. Cancer Res2003; 63:1727 -1730[Abstract/Free Full Text]
  19. Fraser RS, Muller NL, Colman N, Pare PD. Diagnosis of diseases of the chest, 4th ed. Philadelphia, PA: WB Saunders,1999 : 1251-1261

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 Br. J. Radiol.Home page
U WAGNETZ, D PATSIOS, G DARLING, F LAS HERAS, and D HWANG
Tracheal chondrosarcoma -- a rare complication in Maffucci syndrome
Br. J. Radiol., September 1, 2009; 82(981): e178 - e181.
[Abstract] [Full Text] [PDF]

Home page
 RadioGraphicsHome page
C. M. Park, J. M. Goo, H. J. Lee, M. A Kim, C. H. Lee, and M.-J. Kang
Tumors in the Tracheobronchial Tree: CT and FDG PET Features1
RadioGraphics, January 1, 2009; 29(1): 55 - 71.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chong, S.
Right arrow Articles by Han, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chong, S.
Right arrow Articles by Han, J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS