- Email: [email protected]
Submucosal lesions
Submucosal lesions Takao Itoi, MD, Atsushi Sofuni, MD, Fumihide Itokawa, MD, Takayoshi Tsuchiya, MD, Toshio Kurihara, MD, Shujiro Tsuji, MD, Kentaro Ishii, MD, Nobuhito Ikeuchi, MD, Fuminori Moriyasu, MD Tokyo, Japan
Submucosal lesions (SML), which are frequently encountered during endoscopy, are difficult to diagnose because they are covered by normal mucosa. In such cases, although conventional biopsy generally fails to yield diagnostic materials, EUS, which enables intramural scanning of the GI tract, can be diagnostically effective.1-3 Although EUS imaging of SML can provide some data, ie, originating layer, internal echogenicity, and internal echo pattern, it has limited accuracy in distinguishing malignant from benign SML, even when using the Doppler mode. In contrast, a linear-array echoendoscope allows not only diagnostic imaging but also accurate biopsy under real-time imaging. EUS-guided FNA for SML is indicated in cases that are not only diagnosable by conventional endoscopy but especially in those cases that need a distinction to be made between benign and malignant diseases by means of EUS imaging alone.4-8
PROCEDURAL TECHNIQUE TO IMAGE SMLWITH A LINEAR ECHOENDOSCOPE Optimal EUS imaging of an SML requires submersion of the tumors under water. When the lumen cannot be filled by water, compression by the balloon of the tip of the echoendoscope is useful for better imaging. Doppler imaging is helpful in SML. In particular, because large gastric varices may occasionally be polypoid, vessel flow can be detected by using Doppler imaging. A linear-array echoendoscope can correctly identify the gut layer of origin. For better imaging, the US beam should be perpendicularly aimed at the gut wall. The catheter probe EUS is useful for small lesions, although Doppler cannot be used.
PROCEDURAL TECHNIQUE OF EUS-GUIDED FNA FOR SML Maneuvering of the echoendoscope for EUS-guided FNA of SML is similar to that for other lesions. However, because SML are usually hard and mobile, which makes them hard to puncture, a echoendoscope that can force the needle down DISCLOSURE: T. Itoi, A. Sofuni, F. Itokawa, T. Tsuchiya, T. Kurihara, S. Tsuji, K. Ishii, N. Ikeuchi, and F. Moriyasu disclosed no financial relationships relevant to this publication. Copyright ª 2009 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 doi:10.1016/j.gie.2008.12.012
S100 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 2 : 2009
and under the lesion is better for a reliable puncture. Briefly, the aspiration needle is advanced into the lesion under direct EUS visualization. The central stylet is removed, a 10-mL syringe is attached to the hub of the needle, and suction is applied as the needle is moved back and forth within the lesion (the extension and retraction cycle of the needle is repeated 10 times within the lesion in 1 puncture session). In EUS-guided FNA, the Tru-cut needle is not set in the firing position before introduction into the EUS echoendoscope. After the echoendoscope is advanced into the target tissue under EUS visualization, its position is maintained while the spring handle is pulled back until it clicks into the firing position. The 20-mm tissue tray is then fully extended, and the spring-loaded mechanism is triggered, which drives the cutting needle over the tissue tray.9-11 After firing, the biopsy needle is retracted into the sheath, and the entire assembly is removed from the EUS echoendoscope. Although the needle used for EUS-guided FNA depends on the location, size, or characteristics of the lesions, large specimens are better for reliable immunohistochemistry, which enables the differential diagnosis of the lesion. Some endoscopists recommend the use of a Tru-cut needle to obtain reliable specimens when no on-site cytopathologist is present.
ANALYSIS OF EUS-GUIDED FNA SAMPLES To date, several types of immunohistochemical analyses have been performed. In particular, CD34, CD117, smoothmuscle actin, and S100 protein staining are useful for differential diagnosis of SML.12 Flow cytometry or MIB-1 immunostaining are also helpful for diagnosis and for assessing the degree of histologic malignancy of SML. Abbreviation: SML, submucosal lesion.
REFERENCES 1. Yasuda K, Nakajima M, Yoshida S, et al. The diagnosis of submucosal tumors of the stomach by endoscopic ultrasonography. Gastrointest Endosc 1989;35:10-5. 2. Ro¨sch T, Lorenz R, Dancygier H, et al. Endosonographic diagnosis of submucosal upper gastrointestinal tract tumors. Scand J Gastroenterol 1992;27:1-8. 3. Chak A. EUS in submucosal tumors. Gastrointest Endosc 2002;56:S42-8. 4. Vilmann O, Hancke S, Henriksen FW, et al. Endosonographicallyguided fine needle aspiration biopsy of malignant lesions in the upper gastrointestinal tract. Endoscopy 1993;25:523-7. 5. Chang KJ, Katz KD, Durbin TE, et al. Endoscopic ultrasound-guided fine-needle aspiration. Gastrointest Endosc 1994;40:694-9.
www.giejournal.org
Itoi et al 6. Giovannini M, Seitz JF, Monges G, et al. Fine-needle aspiration cytology guided by endoscopic ultrasonography: results in 141 patients. Endoscopy 1995;27:171-7. 7. Gress FG, Hawes RH, Savides TJ, et al. Endoscopic ultrasound-guided fine-needle aspiration biopsy using linear array and radial scanning endosonography. Gastrointest Endosc 1997;45:243-50. 8. Binmoeller KF, Thul R, Rathod V, et al. Endoscopic ultrasoundguided, 18-gauge, fine needle aspiration biopsy of the pancreas using a 2.8 mm channel convex echoendoscope. Gastrointest Endosc 1998;47:121-7. 9. Wiersema MJ, Levy MJ, Harewood GC, et al. Initial experience with EUS-guided Trucut needle biopsy of perigastric organs. Gastrointest Endosc 2002;56:275-8. 10. Itoi T, Itokawa F, Sofuni A, et al. Puncture of solid pancreatic tumors guided by endoscopic ultrasonography: a pilot study series comparing
www.giejournal.org
Submucosal lesions
Tru-Cut and 19-gauge and 22-gauge aspiration needles. Endoscopy 2005;37:362-6. 11. Varadarajulu S, Fraig M, Schmulewitz N, et al. Comparison of EUSguided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration. Endoscopy 2004;36:397-401. 12. Okubo K, Yamao K, Nakamura R, et al. Endoscopic ultrasound-guided fine-needle aspiration biopsy for the diagnosis of gastrointestinal stromal tumors in the stomach. J Gastroenterol 2004;39:747-53.
Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan. This article is from a meeting and has not undergone the GIE peer review process.
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S101
Submucosal lesions (SML), which are frequently encountered during endoscopy, are difficult to diagnose because they are covered by normal mucosa. In such cases, although conventional biopsy generally fails to yield diagnostic materials, EUS, which enables intramural scanning of the GI tract, can be diagnostically effective.1-3 Although EUS imaging of SML can provide some data, ie, originating layer, internal echogenicity, and internal echo pattern, it has limited accuracy in distinguishing malignant from benign SML, even when using the Doppler mode. In contrast, a linear-array echoendoscope allows not only diagnostic imaging but also accurate biopsy under real-time imaging. EUS-guided FNA for SML is indicated in cases that are not only diagnosable by conventional endoscopy but especially in those cases that need a distinction to be made between benign and malignant diseases by means of EUS imaging alone.4-8
PROCEDURAL TECHNIQUE TO IMAGE SMLWITH A LINEAR ECHOENDOSCOPE Optimal EUS imaging of an SML requires submersion of the tumors under water. When the lumen cannot be filled by water, compression by the balloon of the tip of the echoendoscope is useful for better imaging. Doppler imaging is helpful in SML. In particular, because large gastric varices may occasionally be polypoid, vessel flow can be detected by using Doppler imaging. A linear-array echoendoscope can correctly identify the gut layer of origin. For better imaging, the US beam should be perpendicularly aimed at the gut wall. The catheter probe EUS is useful for small lesions, although Doppler cannot be used.
PROCEDURAL TECHNIQUE OF EUS-GUIDED FNA FOR SML Maneuvering of the echoendoscope for EUS-guided FNA of SML is similar to that for other lesions. However, because SML are usually hard and mobile, which makes them hard to puncture, a echoendoscope that can force the needle down DISCLOSURE: T. Itoi, A. Sofuni, F. Itokawa, T. Tsuchiya, T. Kurihara, S. Tsuji, K. Ishii, N. Ikeuchi, and F. Moriyasu disclosed no financial relationships relevant to this publication. Copyright ª 2009 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 doi:10.1016/j.gie.2008.12.012
S100 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 2 : 2009
and under the lesion is better for a reliable puncture. Briefly, the aspiration needle is advanced into the lesion under direct EUS visualization. The central stylet is removed, a 10-mL syringe is attached to the hub of the needle, and suction is applied as the needle is moved back and forth within the lesion (the extension and retraction cycle of the needle is repeated 10 times within the lesion in 1 puncture session). In EUS-guided FNA, the Tru-cut needle is not set in the firing position before introduction into the EUS echoendoscope. After the echoendoscope is advanced into the target tissue under EUS visualization, its position is maintained while the spring handle is pulled back until it clicks into the firing position. The 20-mm tissue tray is then fully extended, and the spring-loaded mechanism is triggered, which drives the cutting needle over the tissue tray.9-11 After firing, the biopsy needle is retracted into the sheath, and the entire assembly is removed from the EUS echoendoscope. Although the needle used for EUS-guided FNA depends on the location, size, or characteristics of the lesions, large specimens are better for reliable immunohistochemistry, which enables the differential diagnosis of the lesion. Some endoscopists recommend the use of a Tru-cut needle to obtain reliable specimens when no on-site cytopathologist is present.
ANALYSIS OF EUS-GUIDED FNA SAMPLES To date, several types of immunohistochemical analyses have been performed. In particular, CD34, CD117, smoothmuscle actin, and S100 protein staining are useful for differential diagnosis of SML.12 Flow cytometry or MIB-1 immunostaining are also helpful for diagnosis and for assessing the degree of histologic malignancy of SML. Abbreviation: SML, submucosal lesion.
REFERENCES 1. Yasuda K, Nakajima M, Yoshida S, et al. The diagnosis of submucosal tumors of the stomach by endoscopic ultrasonography. Gastrointest Endosc 1989;35:10-5. 2. Ro¨sch T, Lorenz R, Dancygier H, et al. Endosonographic diagnosis of submucosal upper gastrointestinal tract tumors. Scand J Gastroenterol 1992;27:1-8. 3. Chak A. EUS in submucosal tumors. Gastrointest Endosc 2002;56:S42-8. 4. Vilmann O, Hancke S, Henriksen FW, et al. Endosonographicallyguided fine needle aspiration biopsy of malignant lesions in the upper gastrointestinal tract. Endoscopy 1993;25:523-7. 5. Chang KJ, Katz KD, Durbin TE, et al. Endoscopic ultrasound-guided fine-needle aspiration. Gastrointest Endosc 1994;40:694-9.
www.giejournal.org
Itoi et al 6. Giovannini M, Seitz JF, Monges G, et al. Fine-needle aspiration cytology guided by endoscopic ultrasonography: results in 141 patients. Endoscopy 1995;27:171-7. 7. Gress FG, Hawes RH, Savides TJ, et al. Endoscopic ultrasound-guided fine-needle aspiration biopsy using linear array and radial scanning endosonography. Gastrointest Endosc 1997;45:243-50. 8. Binmoeller KF, Thul R, Rathod V, et al. Endoscopic ultrasoundguided, 18-gauge, fine needle aspiration biopsy of the pancreas using a 2.8 mm channel convex echoendoscope. Gastrointest Endosc 1998;47:121-7. 9. Wiersema MJ, Levy MJ, Harewood GC, et al. Initial experience with EUS-guided Trucut needle biopsy of perigastric organs. Gastrointest Endosc 2002;56:275-8. 10. Itoi T, Itokawa F, Sofuni A, et al. Puncture of solid pancreatic tumors guided by endoscopic ultrasonography: a pilot study series comparing
www.giejournal.org
Submucosal lesions
Tru-Cut and 19-gauge and 22-gauge aspiration needles. Endoscopy 2005;37:362-6. 11. Varadarajulu S, Fraig M, Schmulewitz N, et al. Comparison of EUSguided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration. Endoscopy 2004;36:397-401. 12. Okubo K, Yamao K, Nakamura R, et al. Endoscopic ultrasound-guided fine-needle aspiration biopsy for the diagnosis of gastrointestinal stromal tumors in the stomach. J Gastroenterol 2004;39:747-53.
Gastroenterology and Hepatology, Tokyo Medical University Hospital, Tokyo, Japan. This article is from a meeting and has not undergone the GIE peer review process.
Volume 69, No. 2 : 2009 GASTROINTESTINAL ENDOSCOPY S101