- Email: [email protected]
EUS for mediastinal disease
EUS for mediastinal disease Thomas J. Savides, MD San Diego, California, USA
TECHNICAL ASPECTS EUS is ideally suited to evaluate lesions found in the posterior mediastinum. In general, these lesions were first identified by a chest CT. Electronic radial array EUS of the posterior mediastinum can quickly provide a nearly 360 view of the posterior mediastinum. Linear-array EUS is ideal for a focused examination with transesophageal FNA. When lung cancer is suspected, the examination will focus on not only the nodal stations but also on infradiaphragmatic sites of metastatic disease, such as the left adrenal gland and liver. The actual technique of transesophageal EUS evaluation of the mediastinum is relatively easy because of the fixed orientation of the structures. In general, little or no air is needed in the transducer balloon. Suction is constantly applied to remove any luminal air and to keep the transducer pressed against the area of interest. The scope is initially placed into the stomach to look at the left adrenal, liver, and celiac region. The scope is then slowly pulled back to look for periesophageal lymph nodes. The examination often focuses on evaluating the subcarinal space (usually 25-30 cm from the incisors), as well as the posterior aortopulmonic window. If lesions are suspected in the paratracheal area, then the scope can be rotated to identify these. The esophagus is actually quite mobile, and, often, by deflecting the scope tip and torquing the scope, even paratracheal or lesions behind the aorta can be visualized and FNA performed. Transesophageal EUS-guided FNA (EUS-FNA) is the easiest of all transintestinal FNA procedures. This is because the scope tip is kept relatively straight, which allows the needle to come out easily (in contrast to lesions in the pancreatic head, which may need significant scope-tip deflection). The scope tip is deflected slightly toward the lesion (by rotating the big wheel backward), which presses the transducer against the lesion. All air is removed from the lumen by using suction. The needle quickly pierces (in a ‘‘staccato’’ fashion) the esophageal wall to enter the lesion. Most mediastinal lesions need, on average, 2 t o 5 passes for diagnostic material, in contrast to pancreatic lesions, which usually require 5 to 7 passes.1-4
In the last few years, endobronchial US has become more widely available and provides unique access to lymph nodes and masses adjacent to the trachea. The combination of transesophageal and transbronchial EUS provides nearly complete mediastinal evaluation.5 Elastography has recently been reported in the evaluation of mediastinal lymph nodes and masses.6 However, the sensitivity and specificity (in the 80%-90% range) is lower than that of transesophageal or transbronchial EUS-FNA (O90% range) and, therefore, still needs further improvement before widespread utilization. The types of diseases that may be detected with EUS are outlined in Table 1.
BENIGN LYMPH NODES Benign lymph nodes are commonly seen in the normal posterior mediastinum, especially in the subcarinal area, which is located 20 to 25 cm from the incisors. These lymph nodes are usually oval or triangular in appearance. EUS frequently visualizes the inner hyperechoic center of the lymph-node hilum, which is not visible in malignant lymph nodes.
Reactive lymph nodes Reactive lymph nodes are usually the result of previous pulmonary infections or inhaled irritants. They have the typical benign EUS features of a draping or triangular appearance but may come to EUS-FNA because their larger size suggests the possibility of lymphoma.
Granulomatous lymph nodes These lymph nodes usually also are larger, benignappearing draping or triangular lymph nodes. EUS-FNA cytology shows collections of palisading histocytes in a background of lymphocytes. The differential diagnosis of a granulomatous lymph node includes sarcoidosis, histoplasmosis, tuberculosis, and coccidioidomycosis. Sometimes there will be calcifications seen in granulomatous lymph nodes, which is suggestive of a chronic benign condition. In cases in which tuberculosis is suspected, polymerase chain reaction testing for mycobacterium tuberculosis should be included with cytology and cultures.
DISCLOSURE: The following author disclosed financial relationships relevant to this publication: T. J. Savides received a single honorarium for speaking from Olympus Corporation.
MALIGNANT LYMPH NODES
Copyright ª 2009 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 doi:10.1016/j.gie.2008.12.008
Malignant lymph nodes tend to appear more round in shape, have a short-axis diameter R 5 mm, a hypoechoic echotexture, and well-demarcated borders.7,8 When all 4
www.giejournal.org
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S97
Mediastinal disease
Savides
MALIGNANT MEDIASTINAL MASSES TABLE 1. Posterior mediastinal lesions that can be diagnosed with EUS Primary pulmonary malignancy Non-small-cell lung cancer Small-cell lung cancer Metastatic cancer from extrapulmonary malignancy
The EUS distinction between a posterior mediastinal mass and a lymph node can be difficult, because some lymph nodes are very large, whereas some masses are very small. In addition, numerous lymph nodes matted together may form a ‘‘mass.’’ Usually a mass is larger than an enlarged lymph node (ie, O3-cm short diameter), but there is no standardized definition.
Lymphoma Reactive lymph nodes Granulomatous disease Sarcoid Histoplasmosis Tuberculosis Neurogenic tumors Duplication cysts Mediastinal abscess or mediastinitis
Lung cancer A primary lung-cancer mass is the most commonly encountered mass adjacent to the esophagus that may undergo EUS-FNA and may be either non-small-cell or small-cell carcinoma.
Metastatic masses Just as with metastatic lymph nodes, metastases from lung, breast, colon, kidney, testicle, cervix, larynx, and esophagus cancer have been diagnosed with transesophageal EUS-FNA.
Cardiovascular lesions Pericardial effusion Left atrial myxoma Left atrial thrombus Aortic aneurysm Pleural effusions
features are present, the risk of malignancy is 80% to 100%, but, because only 25% of malignant lymph nodes have all these features, it is important to consider EUS-FNA to obtain diagnostic material.8,9 The overall sensitivity and specificity of EUS-FNA for diagnosing malignant lymph nodes is O90%.10-13 The risk of transesophageal EUSFNA is!1%, and includes bleeding, perforation, infection, or mediastinitis.13
Metastatic lymph nodes The most common primary site for metastatic mediastinal lymph nodes is lung cancer, of which 80% is non-small-cell lung cancer and 20% small-cell carcinoma. EUS-FNA has also been reported to diagnosis metastases from esophagus, breast, colon, kidney, testis, larynx, pancreas, and liver cancer.
Lymphoma Diffuse mediastinal adenopathy raises the possibility of lymphoma. EUS-FNA cytology, especially with flow cytometry and immunocytochemistry, can usually diagnosis lymphoma. Occasionally, EUS-guided Tru-cut biopsies may be needed to provide material for architectural detail to help diagnosis low-grade lymphomas, which might otherwise not be diagnosed with cytology.14 S98 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 2 : 2009
Neurogenic tumors and mediastinal sarcomas Primary neoplasms of the posterior mediastinum are rare. Approximately 75% are neurogenic and arise from peripheral nerves (schwannoma, neurilemmoma, neurofibroma, or nerve-sheath tumors), sympathetic ganglia (ganglioneuroma, ganglioneuroblastoma, or neuroblastoma), parasympathetic ganglia (paraganglionoma), or sarcoma. EUS-FNA cytology and Tru-cut biopsy have been reported to diagnose these lesions.
BENIGN MEDIASTINAL MASSES Mediastinal cysts Most posterior mediastinal cysts are asymptomatic and are discovered incidentally during other imaging studies. Cysts generally appear as round or oval anechoic structures, with acoustic enhancement. Occasionally, cysts with large amounts of internal debris or mucus may be confused with a mass. Transesophageal EUS-FNA should not be routinely performed in obvious mediastinal cysts because of the risk of infection. If FNA of a lesion yields fluid and/or mucus, then the cyst should be aspirated as completely as possible (sometimes difficult because of viscous material) and IV antibiotics given, followed by several days of oral antibiotics. Case series in which aspirated cysts received antibiotics show low rates of infection.15 Infection seems to especially increase with the use of a Tru-cut needle biopsy of mediastinal cysts.16
Mediastinitis and abscess EUS has been reported to detect abscesses. These usually appear as inhomogeneous, well-demarcated, hypoechoic areas. There have been reports of both FNA www.giejournal.org
Savides
(with a goal to drain as much fluid as possible) and placement of pigtail stents to drain abscesses.17,18
CARDIOTHORACIC ABNORMALITIES Pleural effusions are occasionally seen during EUS. These are almost always right-sided pleural effusions because of patient positioning in the left lateral decubitus position. These can be either benign or malignant effusions, and, if clinically indicated, then EUS-FNA can be performed. On occasion, cardiac lesions may be identified. These include pericardial effusion, atrial thrombus, atrial myxoma, and thoracic aneurysms. The operating characteristics of the GI echoendoscope have too short an optimal focal distance to see cardiac structures well and, therefore, dedicated transesophageal echoendoscopes that image at lower frequency will be better suited for imaging cardiac lesions. There have been reports of transesophageal EUS-FNA of left atrial lesions.
CONCLUSIONS Transesophageal EUS is uniquely suited to visualize and biopsy a variety of pathologic conditions in the posterior mediastinum. It is important to understand the types of pathology that may be encountered, because this may alter the decision to perform FNA or to guide the laboratory evaluation of the obtained specimen. Abbreviation: EUS-FNA, EUS-guided FNA.
REFERENCES 1. Emery SC, Savides TJ, Behling CA. Utility of immediate evaluation of endoscopic ultrasound-guided transesophageal fine needle aspiration of mediastinal lymph nodes. Acta Cytol 2004;48:630-4. 2. LeBlanc JK, Ciaccia D, Al-Assi MT, et al. Optimal number of EUS-guided fine needle passes needed to obtain a correct diagnosis. Gastrointest Endosc 2004;59:475-81.
www.giejournal.org
Mediastinal disease 3. Wallace MB, Kennedy T, Durkalski V, et al. Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy. Gastrointest Endosc 2001;54:441-7. 4. Erickson RA, Sayage-Rabie L, Beissner RS. Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies. Gastrointest Endosc 2000;51:184-90. 5. Wallace MB, Pascual JM, Raimondo M, et al. Minimally invasive endoscopic staging of suspected lung cancer. JAMA 2008;299:540-6. 6. Janssen J, Dietrich CF, Will U, et al. Endosonographic elastography in the diagnosis of mediastinal lymph nodes. Endoscopy 2007;39:952-7. 7. Wiersema MJ, Hassig WM, Hawes RH, et al. Mediastinal lymph node detection with endosonography. Gastrointest Endosc 1993;39:788-93. 8. Catalano MF, Sivak MV Jr, Rice T, et al. Endosonographic features predictive of lymph node metastasis. Gastrointest Endosc 1994;40:442-6. 9. Bhutani MS, Hawes RH, Hoffman BJ. A comparison of the accuracy of echo features during endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration for diagnosis of malignant lymph node invasion. Gastrointest Endosc 1997;45:474-9. 10. Gress FG, Savides TJ, Sandler A, et al. Endoscopic ultrasonography, fine-needle aspiration biopsy guided by endoscopic ultrasonography, and computed tomography in the preoperative staging of non-smallcell lung cancer: a comparison study. Ann Intern Med 1997;127:60412. 11. Wallace MB, Fritscher-Ravens A, Savides TJ. Endoscopic ultrasound for the staging of non-small-cell lung cancer. Endoscopy 2003;35:606-10. 12. Savides TJ, Perricone A. Impact of EUS-guided FNA of enlarged mediastinal lymph nodes on subsequent thoracic surgery ratesGastrointest Endosc 2004;60:340-6. 13. Micames CG, McCrory DC, Pavey DA, et al. Endoscopic ultrasoundguided fine-needle aspiration for non-small cell lung cancer staging: a systematic review and metaanalysis. Chest 2007;131:539-48. 14. Levy MJ, Wiersema MJ. EUS-guided Trucut biopsy. Gastrointest Endosc 2005;62:417-26. 15. Fazel A, Moezardalan K, Varadarajulu S, et al. The utility and the safety of EUS-guided FNA in the evaluation of duplication cysts. Gastrointest Endosc 2005;62:575-80. 16. Wildi SM, Hoda RS, Fickling W, et al. Diagnosis of benign cysts of the mediastinum: the role and risks of EUS and FNA. Gastrointest Endosc 2003;58:362-8. 17. Kahaleh M, Yoshida C, Kane L, et al. EUS drainage of a mediastinal abscess. Gastrointest Endosc 2004;60:158-60. 18. Wehrmann T, Stergiou N, Vogel B, et al. Endoscopic debridement of paraesophageal, mediastinal abscesses: a prospective case series. Gastrointest Endosc 2005;62:344-9.
University of California San Diego, San Diego, California, USA. This article is from a meeting and has not undergone the GIE peer review process.
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S99
TECHNICAL ASPECTS EUS is ideally suited to evaluate lesions found in the posterior mediastinum. In general, these lesions were first identified by a chest CT. Electronic radial array EUS of the posterior mediastinum can quickly provide a nearly 360 view of the posterior mediastinum. Linear-array EUS is ideal for a focused examination with transesophageal FNA. When lung cancer is suspected, the examination will focus on not only the nodal stations but also on infradiaphragmatic sites of metastatic disease, such as the left adrenal gland and liver. The actual technique of transesophageal EUS evaluation of the mediastinum is relatively easy because of the fixed orientation of the structures. In general, little or no air is needed in the transducer balloon. Suction is constantly applied to remove any luminal air and to keep the transducer pressed against the area of interest. The scope is initially placed into the stomach to look at the left adrenal, liver, and celiac region. The scope is then slowly pulled back to look for periesophageal lymph nodes. The examination often focuses on evaluating the subcarinal space (usually 25-30 cm from the incisors), as well as the posterior aortopulmonic window. If lesions are suspected in the paratracheal area, then the scope can be rotated to identify these. The esophagus is actually quite mobile, and, often, by deflecting the scope tip and torquing the scope, even paratracheal or lesions behind the aorta can be visualized and FNA performed. Transesophageal EUS-guided FNA (EUS-FNA) is the easiest of all transintestinal FNA procedures. This is because the scope tip is kept relatively straight, which allows the needle to come out easily (in contrast to lesions in the pancreatic head, which may need significant scope-tip deflection). The scope tip is deflected slightly toward the lesion (by rotating the big wheel backward), which presses the transducer against the lesion. All air is removed from the lumen by using suction. The needle quickly pierces (in a ‘‘staccato’’ fashion) the esophageal wall to enter the lesion. Most mediastinal lesions need, on average, 2 t o 5 passes for diagnostic material, in contrast to pancreatic lesions, which usually require 5 to 7 passes.1-4
In the last few years, endobronchial US has become more widely available and provides unique access to lymph nodes and masses adjacent to the trachea. The combination of transesophageal and transbronchial EUS provides nearly complete mediastinal evaluation.5 Elastography has recently been reported in the evaluation of mediastinal lymph nodes and masses.6 However, the sensitivity and specificity (in the 80%-90% range) is lower than that of transesophageal or transbronchial EUS-FNA (O90% range) and, therefore, still needs further improvement before widespread utilization. The types of diseases that may be detected with EUS are outlined in Table 1.
BENIGN LYMPH NODES Benign lymph nodes are commonly seen in the normal posterior mediastinum, especially in the subcarinal area, which is located 20 to 25 cm from the incisors. These lymph nodes are usually oval or triangular in appearance. EUS frequently visualizes the inner hyperechoic center of the lymph-node hilum, which is not visible in malignant lymph nodes.
Reactive lymph nodes Reactive lymph nodes are usually the result of previous pulmonary infections or inhaled irritants. They have the typical benign EUS features of a draping or triangular appearance but may come to EUS-FNA because their larger size suggests the possibility of lymphoma.
Granulomatous lymph nodes These lymph nodes usually also are larger, benignappearing draping or triangular lymph nodes. EUS-FNA cytology shows collections of palisading histocytes in a background of lymphocytes. The differential diagnosis of a granulomatous lymph node includes sarcoidosis, histoplasmosis, tuberculosis, and coccidioidomycosis. Sometimes there will be calcifications seen in granulomatous lymph nodes, which is suggestive of a chronic benign condition. In cases in which tuberculosis is suspected, polymerase chain reaction testing for mycobacterium tuberculosis should be included with cytology and cultures.
DISCLOSURE: The following author disclosed financial relationships relevant to this publication: T. J. Savides received a single honorarium for speaking from Olympus Corporation.
MALIGNANT LYMPH NODES
Copyright ª 2009 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 doi:10.1016/j.gie.2008.12.008
Malignant lymph nodes tend to appear more round in shape, have a short-axis diameter R 5 mm, a hypoechoic echotexture, and well-demarcated borders.7,8 When all 4
www.giejournal.org
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S97
Mediastinal disease
Savides
MALIGNANT MEDIASTINAL MASSES TABLE 1. Posterior mediastinal lesions that can be diagnosed with EUS Primary pulmonary malignancy Non-small-cell lung cancer Small-cell lung cancer Metastatic cancer from extrapulmonary malignancy
The EUS distinction between a posterior mediastinal mass and a lymph node can be difficult, because some lymph nodes are very large, whereas some masses are very small. In addition, numerous lymph nodes matted together may form a ‘‘mass.’’ Usually a mass is larger than an enlarged lymph node (ie, O3-cm short diameter), but there is no standardized definition.
Lymphoma Reactive lymph nodes Granulomatous disease Sarcoid Histoplasmosis Tuberculosis Neurogenic tumors Duplication cysts Mediastinal abscess or mediastinitis
Lung cancer A primary lung-cancer mass is the most commonly encountered mass adjacent to the esophagus that may undergo EUS-FNA and may be either non-small-cell or small-cell carcinoma.
Metastatic masses Just as with metastatic lymph nodes, metastases from lung, breast, colon, kidney, testicle, cervix, larynx, and esophagus cancer have been diagnosed with transesophageal EUS-FNA.
Cardiovascular lesions Pericardial effusion Left atrial myxoma Left atrial thrombus Aortic aneurysm Pleural effusions
features are present, the risk of malignancy is 80% to 100%, but, because only 25% of malignant lymph nodes have all these features, it is important to consider EUS-FNA to obtain diagnostic material.8,9 The overall sensitivity and specificity of EUS-FNA for diagnosing malignant lymph nodes is O90%.10-13 The risk of transesophageal EUSFNA is!1%, and includes bleeding, perforation, infection, or mediastinitis.13
Metastatic lymph nodes The most common primary site for metastatic mediastinal lymph nodes is lung cancer, of which 80% is non-small-cell lung cancer and 20% small-cell carcinoma. EUS-FNA has also been reported to diagnosis metastases from esophagus, breast, colon, kidney, testis, larynx, pancreas, and liver cancer.
Lymphoma Diffuse mediastinal adenopathy raises the possibility of lymphoma. EUS-FNA cytology, especially with flow cytometry and immunocytochemistry, can usually diagnosis lymphoma. Occasionally, EUS-guided Tru-cut biopsies may be needed to provide material for architectural detail to help diagnosis low-grade lymphomas, which might otherwise not be diagnosed with cytology.14 S98 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 2 : 2009
Neurogenic tumors and mediastinal sarcomas Primary neoplasms of the posterior mediastinum are rare. Approximately 75% are neurogenic and arise from peripheral nerves (schwannoma, neurilemmoma, neurofibroma, or nerve-sheath tumors), sympathetic ganglia (ganglioneuroma, ganglioneuroblastoma, or neuroblastoma), parasympathetic ganglia (paraganglionoma), or sarcoma. EUS-FNA cytology and Tru-cut biopsy have been reported to diagnose these lesions.
BENIGN MEDIASTINAL MASSES Mediastinal cysts Most posterior mediastinal cysts are asymptomatic and are discovered incidentally during other imaging studies. Cysts generally appear as round or oval anechoic structures, with acoustic enhancement. Occasionally, cysts with large amounts of internal debris or mucus may be confused with a mass. Transesophageal EUS-FNA should not be routinely performed in obvious mediastinal cysts because of the risk of infection. If FNA of a lesion yields fluid and/or mucus, then the cyst should be aspirated as completely as possible (sometimes difficult because of viscous material) and IV antibiotics given, followed by several days of oral antibiotics. Case series in which aspirated cysts received antibiotics show low rates of infection.15 Infection seems to especially increase with the use of a Tru-cut needle biopsy of mediastinal cysts.16
Mediastinitis and abscess EUS has been reported to detect abscesses. These usually appear as inhomogeneous, well-demarcated, hypoechoic areas. There have been reports of both FNA www.giejournal.org
Savides
(with a goal to drain as much fluid as possible) and placement of pigtail stents to drain abscesses.17,18
CARDIOTHORACIC ABNORMALITIES Pleural effusions are occasionally seen during EUS. These are almost always right-sided pleural effusions because of patient positioning in the left lateral decubitus position. These can be either benign or malignant effusions, and, if clinically indicated, then EUS-FNA can be performed. On occasion, cardiac lesions may be identified. These include pericardial effusion, atrial thrombus, atrial myxoma, and thoracic aneurysms. The operating characteristics of the GI echoendoscope have too short an optimal focal distance to see cardiac structures well and, therefore, dedicated transesophageal echoendoscopes that image at lower frequency will be better suited for imaging cardiac lesions. There have been reports of transesophageal EUS-FNA of left atrial lesions.
CONCLUSIONS Transesophageal EUS is uniquely suited to visualize and biopsy a variety of pathologic conditions in the posterior mediastinum. It is important to understand the types of pathology that may be encountered, because this may alter the decision to perform FNA or to guide the laboratory evaluation of the obtained specimen. Abbreviation: EUS-FNA, EUS-guided FNA.
REFERENCES 1. Emery SC, Savides TJ, Behling CA. Utility of immediate evaluation of endoscopic ultrasound-guided transesophageal fine needle aspiration of mediastinal lymph nodes. Acta Cytol 2004;48:630-4. 2. LeBlanc JK, Ciaccia D, Al-Assi MT, et al. Optimal number of EUS-guided fine needle passes needed to obtain a correct diagnosis. Gastrointest Endosc 2004;59:475-81.
www.giejournal.org
Mediastinal disease 3. Wallace MB, Kennedy T, Durkalski V, et al. Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy. Gastrointest Endosc 2001;54:441-7. 4. Erickson RA, Sayage-Rabie L, Beissner RS. Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies. Gastrointest Endosc 2000;51:184-90. 5. Wallace MB, Pascual JM, Raimondo M, et al. Minimally invasive endoscopic staging of suspected lung cancer. JAMA 2008;299:540-6. 6. Janssen J, Dietrich CF, Will U, et al. Endosonographic elastography in the diagnosis of mediastinal lymph nodes. Endoscopy 2007;39:952-7. 7. Wiersema MJ, Hassig WM, Hawes RH, et al. Mediastinal lymph node detection with endosonography. Gastrointest Endosc 1993;39:788-93. 8. Catalano MF, Sivak MV Jr, Rice T, et al. Endosonographic features predictive of lymph node metastasis. Gastrointest Endosc 1994;40:442-6. 9. Bhutani MS, Hawes RH, Hoffman BJ. A comparison of the accuracy of echo features during endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration for diagnosis of malignant lymph node invasion. Gastrointest Endosc 1997;45:474-9. 10. Gress FG, Savides TJ, Sandler A, et al. Endoscopic ultrasonography, fine-needle aspiration biopsy guided by endoscopic ultrasonography, and computed tomography in the preoperative staging of non-smallcell lung cancer: a comparison study. Ann Intern Med 1997;127:60412. 11. Wallace MB, Fritscher-Ravens A, Savides TJ. Endoscopic ultrasound for the staging of non-small-cell lung cancer. Endoscopy 2003;35:606-10. 12. Savides TJ, Perricone A. Impact of EUS-guided FNA of enlarged mediastinal lymph nodes on subsequent thoracic surgery ratesGastrointest Endosc 2004;60:340-6. 13. Micames CG, McCrory DC, Pavey DA, et al. Endoscopic ultrasoundguided fine-needle aspiration for non-small cell lung cancer staging: a systematic review and metaanalysis. Chest 2007;131:539-48. 14. Levy MJ, Wiersema MJ. EUS-guided Trucut biopsy. Gastrointest Endosc 2005;62:417-26. 15. Fazel A, Moezardalan K, Varadarajulu S, et al. The utility and the safety of EUS-guided FNA in the evaluation of duplication cysts. Gastrointest Endosc 2005;62:575-80. 16. Wildi SM, Hoda RS, Fickling W, et al. Diagnosis of benign cysts of the mediastinum: the role and risks of EUS and FNA. Gastrointest Endosc 2003;58:362-8. 17. Kahaleh M, Yoshida C, Kane L, et al. EUS drainage of a mediastinal abscess. Gastrointest Endosc 2004;60:158-60. 18. Wehrmann T, Stergiou N, Vogel B, et al. Endoscopic debridement of paraesophageal, mediastinal abscesses: a prospective case series. Gastrointest Endosc 2005;62:344-9.
University of California San Diego, San Diego, California, USA. This article is from a meeting and has not undergone the GIE peer review process.
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S99