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EMR of ileal adenoma: Report of two cases
EMR of ileal adenoma
K Tsuchida, N Okayama, Y Yokoyama, et al.
8. Bhasin DK, Poddar U. Endoscopic management of chronic pancreatitis. In: Bhutani MS, Tandon RK, editors. Advances in gastrointestinal endoscopy. 1st ed. New Delhi: Jaypee Brothers Medical Publishers; 2001. p. 284-302. 9. Bhasin DK, Sriram PVJ, Nagi B, Varma V, Singh K. Endoscopic stenting of minor papilla for symptomatic pancreatic divisum. Indian J Gastroenterol 1997;16:30-1. 10. Bhasin DK, Dhavan S, Sriram PVJ, Nagi B, Varma V, Singh G, et al. Endoscopic management of pancreatic diseases. Indian J Gastroenterol 1997;16:151-2. 11. Buchler M, Friess H, Bittner R, Roscher R, Krautzberger W, Muller M, et al. Duodenum preserving pancreatic head resection: Long-term results. J Gastrointest Surg 1997;1:13-7. 12. Nealon WH, Thompson JC. Progressive loss of pancreatic function in chronic pancreatitis is delayed by main duct decompression. Ann Surg 1993;217:458-68.
13. Sidhu SS, Nundy S, Tandon RK. The effect of the modified Puestow procedure on diabetes in patients with tropical chronic pancreatitis: a positive study. Am J Gastroenterol 2001;96:107-11. 14. Sato T, Miyashita E, Yamauchi H, Matsuno S. The role of surgical treatment for chronic pancreatitis. Ann Surg 1986; 203:266-71. 15. Adamek HE, Jakobs R, Buttmann A, Adamek MU, Schneider ARJ, Riemann JF. Long term follow up of patients with chronic pancreatitis and pancreatic stones treated with extracorporeal shock wave lithotripsy. Gut 1999;45:402-6. 16. Ammann RW, Akovbiantz A, Largiader F, Scheueler G. Course and outcome of chronic pancreatitis. Longitudinal study of a mixed medical-surgical series of 245 patients. Gastroenterology 1984;86:820-7.
EMR of ileal adenoma: report of two cases Kenji Tsuchida, MD, Naotsuka Okayama, MD, Yoshifumi Yokoyama, MD, Takashi Joh, MD, Kyoji Seno, MD, Hirotaka Ohara, MD, Makoto Sasaki, MD, Hiromi Kataoka, MD, Fuminori Okumura, MD, Makoto Itoh, MD
Various types of malignant tumor, such as lymphoma and carcinoma, arise in the terminal ileum,1 but adenoma is rare in this segment of the small intestine. Two cases are reported in which an adenoma in the terminal ileum was removed by EMR. Endoscopic and stereomicroscopic findings are presented. The clinical benefit of EMR for ileal adenoma is discussed. CASE REPORT Case 1 A 65-year-old man presented with hematochezia. There was a history of laparotomy 24 years earlier for duodenal ulcer. The family history was unremarkable. At a prior colonoscopy, 5 colonic polyps and one ileal polyp were found, and the patient was referred for further evaluation and treatment. The abdomen was soft and flat, a surgical scar was present, and there was no tenderness or palpable mass. Laboratory data included an alkaline phosphatase of 274 U/L (normal: 60-230 U/L) and carcinoembryonic antigen level of 9.3 ng/mL (<5 ng/mL). Colonoscopy revealed a slightly white, flat-elevated 7mm tumor with a central depression and slightly irregular Current affiliations: Internal Medicine, Nagoya City Johsai Hospital, Nagoya City University Graduate School of Medical Sciences, Department of Internal Medicine and Bioregulation, Nagoya, Japan. Reprint requests: Kenji Tsuchida, MD, PhD, Internal Medicine, Nagoya City Johsai Hospital, 4-1 Kitabata-cho, Nakamura-ku, Nagoya 453-0815, Japan. Copyright Ó 2004 by the American Society for Gastrointestinal Endoscopy 0016-5107/$30.00 PII: S0016-5107(03)02820-7 VOLUME 59, NO. 3, 2004
Figure 1. A, Endoscopic view, showing ileal adenoma (Case 1). B, Chromoendoscopic view of ileal adenoma. surface in the ileum 8 cm from the ileocecal valve (Fig. 1A). Chromoscopy (0.08% indigo carmine) demonstrated irregularity of the tumor surface (Fig. 1B). There seemed to be no invasion into the submucosal layer, because probing with a forceps disclosed that the lesion was mobile. Biopsy specimens revealed the tumor to be an adenoma. Barium GASTROINTESTINAL ENDOSCOPY
443
K Tsuchida, N Okayama, Y Yokoyama, et al.
EMR of ileal adenoma
Figure 4. Photomicrograph of resection specimen (Case 1) (H&E, orig. mag. 3 5).
Figure 2. Barium-contrast radiograph, showing ileal tumor (arrow) (Case 1).
colonoscope. By using a needle forceps (NM-4U; Olympus Optical Co., Ltd., Tokyo, Japan), 3 mL of saline solution were injected into the submucosa at the orad side of the tumor until it was completely elevated. The top half of the elevated mucosa, including the entire tumor, then was resected electrosurgically by using a hexagonal snare (SD6U; Olympus), a generator setting of 3 (PSD-10 generator; Olympus), and cutting current. Residual colonic polyps, all adenomas, also were resected. No complication was encountered during the endoscopic treatment or at 5 years’ follow-up. The EMR specimen (17 3 14 mm) was stained with Mayers-hematoxylin for 30 seconds and washed with water. The mucosal surface then was observed by using a stereomicroscope (SMZ-U ZOOM 1:10; Nikon, Tokyo, Japan). This revealed an abnormal pit pattern (Fig. 3) that was slightly branched but not markedly irregular, suggesting an adenoma instead of carcinoma. The mucosa around the tumor was normal in appearance. Histopathologic examination demonstrated an adenoma with moderate dysplasia that was confined to the mucosal layer (Fig. 4). The margins were free of tumor, and there was no invasion of veins or lymph vessels. Barium-contrast radiography of the small bowel 11 days after EMR revealed no stenosis of the terminal ileum. The patient remains well at 5 years after EMR. Case 2
Figure 3. Stereomicroscopic view of resection specimen (arrowheads) (Case 1) (Mayers-hematoxylin, orig. mag. 3 1.3). contrast radiography also demonstrated the lesion as being round and polypoid (Fig. 2). The source of the hematochezia was a hemorrhoid. Based on the results of the examinations, a decision was made to treat the lesion by EMR. Informed consent was obtained. EMR was performed with a standard video444
GASTROINTESTINAL ENDOSCOPY
A 65-year-old man was referred when colonoscopy, performed as a surveillance examination for colonic polyps, revealed an elevated tumor in the ileum 2 cm from the ileocecal valve. Two adenomas had been removed colonoscopically from the colon 1 year earlier. He also had undergone chemotherapy for an axillary rhabdomyosarcoma 3 years previously. Family history was unremarkable. The abdomen was soft, non-tender, and there was no mass palpable. There was no evidence of recurrence of the axillary tumor. Standard laboratory test results were within normal ranges. VOLUME 59, NO. 3, 2004
EMR of ileal adenoma
K Tsuchida, N Okayama, Y Yokoyama, et al.
Figure 6. Photomicrograph of resection specimen (Case 2) (H&E, orig. mag. 34). Figure 5. Endoscopic view, showing ileal tumor (Case 2).
Colonoscopy revealed a semipedunculated tumor with a slightly irregular surface and focal red spots in the terminal ileum (Fig. 5). The lesion moved in response to probing with a forceps and did not seem to invade the submucosa. After informed consent was obtained, the tumor was completely resected by EMR, without complication. The tumor (6 3 5 3 5 mm) was, by histopathologic evaluation, a tubulovillous adenoma with moderate dysplasia (Fig. 6). At 16 months’ follow-up, there was no stenosis at the EMR site. The patient remains well at 5 years after EMR.
DISCUSSION Adenoma in the small intestine is rare. Many of these benign tumors of the small bowel do not cause symptoms and are discovered only incidentally at autopsy.1 However, O’Brien2 noted, in 1973, that benign tumors in the small bowel were being found more frequently because of more aggressive examination of the ileocecal area. In fact, 7 cases of ileal adenoma have been reported in Japan,3-9 and all of these lesions, including those in the present two cases, were detected by screening colonoscopy or barium-contrast radiography. Three of the 9 patients were asymptomatic, and the lesions were less than 1 cm in size. These observations suggest that ileal adenoma may be more common than is appreciated. Machella1 noted that adenoma was the most common benign tumor found in the ileum incidentally at autopsy. As in the two cases presented, examination of the terminal ileum at screening colonoscopy may occasionally reveal an adenoma. The endoscopic appearance of submucosa-invasive ileal cancer includes irregular nodules with friability and converging mucosal folds.10,11 In our first patient, chromoscopy clearly revealed the granular surface of the tumor, but no erosion or bleeding was VOLUME 59, NO. 3, 2004
observed. The endoscopic findings may be important for distinguishing cancer from adenoma. A case of ileal adenoma with high-grade dysplasia involving an ileocecal valve was previously described by us.12 Stereomicroscopic examination of the tumor surface in that case demonstrated a gyrus-like or branched pit pattern with irregularity, suggesting high-grade dysplasia or carcinoma. In contrast, the lesion in the first case reported did not have an irregular mucosal pit pattern, a finding that suggested adenoma. The lesion proved to be an adenoma with moderate dysplasia. Thus, an irregular surface pit pattern also may distinguish cancer from adenoma. Five of 43 jejunal and ileal adenocarcinomas (about 12%) apparently originated from adenomatous lesions in the study of Bridge and Perzin13 Although the frequency of malignant change in benign tumors of the small intestine has not been established definitively, it is estimated from available data that about 7% of adenomatous polyps become malignant.1 Perzin and Bridge14 suggested that all adenomas of the small intestine be resected, because many adenocarcinomas of the small bowel arise in pre-existing adenomas. Based on these data, it is presumed that excision of ileal adenomas is beneficial by preventing progression to cancer. Many ileal cancers still are discovered when in an advanced stage, in which case the prognosis and 5-year survival rate for patients is extremely poor.15 However, with greater awareness, it is possible that more ileal cancers will be diagnosed when in an early stage, thereby improving overall survival.15 Bridge and Perzin13 found that the prognosis for patients with primary jejunal or ileal carcinoma correlated with depth of tumor invasion, lymph node metastasis, and tumor size. Two of their patients with GASTROINTESTINAL ENDOSCOPY
445
K Tsuchida, N Okayama, Y Yokoyama, et al.
neoplasms that invaded only into the submucosa appeared to be cured. There are 6 cases reported from Japan of ileal cancer that was found in an early stage (two intramucosal, 4 submucosal invasion).10,11,16-18 The patients with these cancers, which were located within 10 cm of the ileocecal valve, were cured by conventional surgery. There was no lymph node metastasis in any patient. These results suggest that early detection and surgical treatment of ileal cancer can improve the prognosis for patients. EMR has been used to treat high-grade dysplasia or intramucosal carcinoma of esophagus, stomach, duodenum, and colorectum, including on the ileocecal valve.12 Tada et al.19 reported that polypectomy for polyps of the small intestine had not been performed before 1982 because of the technical difficulties associated with endoscopy of the small intestine. Polypectomy in the small bowel also was considered to be associated with a high risk of perforation, because the small intestinal wall is relatively thin.19 However, after demonstrating that the small intestinal wall was resistant to electrosurgical perforation in animal experiments, Tada et al.19 suggested that electrosurgical removal of small bowel polyps by polypectomy is safe when performed by a skilled endoscopist. Generally, EMR of small elevated lesions is technically easy. Because many small intestinal adenomas reportedly are pedunculated or semipedunculated,20 it is thought that these lesions can be easily removed by EMR. The adenomas in the two cases presented were semipedunculated and flat-elevated lesions, and EMR was successful with no complication because the tumors were smaller than 1 cm. The most important aspect of the EMR procedure is injection of a sufficient volume of saline solution into the submucosa to elevate the lesion completely, in which case, the entire tumor can be resected without injury to the muscle layer.21 ACKNOWLEDGMENTS We thank Dr. Takaaki Nakamura of the Pathology Department of Kainan Hospital, Aichi, Japan, for his assistance with the histopathologic findings for the resected tumors. REFERENCES 1. Machella TE. Tumor of the small intestine. In: Bockus HL, ed. Gastroenterology. Vol. 2. 2nd ed. Philadelphia: Saunders; 1964. p. 176-204. 2. O’Brien TF Jr. Primary tumors and vascular malformations. Philadelphia: Saunders; 1973. p. 959-70. 3. Matsumoto K, Matsumoto K, Takeuchi K, Matsumoto K, Nakayama O, Kitagawa T, et al. Ileal adenomas diagnosed preoperatively by endoscopic examination after desintussception [in Japanese with English abstract]. Gastroenterol Endosc 1986;28:1627-32. 446
GASTROINTESTINAL ENDOSCOPY
EMR of ileal adenoma
4. Hoshino T, Watahiki H, Tatami M, Dodo S, Yamamoto H, Higuchi T, et al. A case of ileal adenoma prolapsed into the colon [in Japanese with English abstract]. Gastroenterol Endosc 1994;36:380-5. 5. Kitsukawa K, Tateyama M, Higashionna A, Shigeno Y, Kinjo F, Saito A, et al. A case of adenoma of the ileum diagnosed preoperatively by endoscopic examination [in Japanese with English abstract]. Gastroenterol Endosc 1990;32:628-31. 6. Yamagiwa H, Tomiyama H, Matsumoto K. A case of small bowel adenoma causing invagination [Japanese]. Sougou Rinsho 1989;38:582-4. 7. Hidaka H, Igarashi M, Nakai H, Kikuchi S, Katsumata T, Saigenji K, et al. A case of interssusception caused by ileal adenoma [in Japanese with English abstract]. Gastroenterol Endosc 1994;36:776-81. 8. Ohmori S, Terashima H, Masuda T, Sakakura K, Hatada K. A case of intussusception in an adult due to an adenoma of the ileum [Japanese]. Mie-igaku 1992;36:447-50. 9. Suzuki Y, Honma T, Ajioka Y, Yoshida H, Kobayashi M, Nakamura A, et al. Diminutive adenoma and intramucosal carcinoma of the terminal ileum found in routine colonoscopy, report of a case [in Japanese with English abstract]. Stomach and Intestine 2001;36:895-8. 10. Ozeki Y, Tsuchiya H, Suzuki M, Shimokawa K, Hayashi M, Sekino T. Early carcinoma of the ileum diagnosed preoperatively, report of a case [in Japanese with English abstract]. Stomach and Intestine 1994;29:1207-13. 11. Tsuchida K, Goto K, Shiraki S, Okayama Y, Hamada S, Iida M, et al. Early carcinoma of the ileum diagnosed preoperatively-report of a case [in Japanese with English abstract]. Gastroenterol Endosc 1995;37:1664-8. 12. Tsuchida K, Joh T, Okayama N, Yokoyama Y, Seno K, Okumura F, et al. Ileal adenoma with high-grade dysplasia involving the ileocecal valve treated by endoscopic mucosal resection: a case report. Gastrointest Endosc 2002;55:125-8. 13. Bridge MF, Perzin KH. Primary adenocarcinoma of the jejunum and ileum. Cancer 1975;36:1876-87. 14. Perzin KH, Bridge MF. Adenomas of the small intestine: a clinicopathological review of 51 cases and a study of their relationship to carcinoma. Cancer 1981;48:799-819. 15. Bauer RL, Palmer ML, Bauer AM, Nava HR, Douglass HO Jr. Adenocarcinoma of the small intestine: 21-year review of diagnosis, treatment, and prognosis. Ann Surg Oncol 1994; 1:183-8. 16. Itano S, Horiki S, Terada N, Endo A, Urakami M, Gotohda N, et al. Two cases of early cancer of ileum diagnosed definitively with colonoscopy before operation [in Japanese with English abstract]. Gastroenterol Endosc 2001;43:2017-25. 17. Endoh K, Yamazaki M, Kuzushima T, Fukao S, Yokota H, Nakano S. Early cancer of the ileum diagnosed by colonoscopy, report of a case [in Japanese with English abstract]. Gastroenterol Endosc 1997;39:79-83. 18. Tsuchida K, Yokoyama Y, Itoh M, Kobayashi K, Nakamura T, Okayama N, et al. Early carcinoma of the ileum diagnosed preoperatively, report of a case [in Japanese with English abstract]. Stomach and Intestine 1997;32:1237-43. 19. Tada M, Misaki F, Akasaka Y, Kawai K. Endoscopic polypectomy for the removal of polyps of the small intestine. Gastroenterologia Japonica 1982;17:177-81. 20. Rankin FW, Newell CE. Benign tumors of the small intestine, report of twenty-four cases. Surg Gynecol Obstet 1933;57: 501-7. 21. Kanamori T, Itoh M, Yokoyama Y, Tsuchida K. Injectionincision-assisted snare resection of large sessile colorectal polyps. Gastrointest Endosc 1996;43:189-95. VOLUME 59, NO. 3, 2004
K Tsuchida, N Okayama, Y Yokoyama, et al.
8. Bhasin DK, Poddar U. Endoscopic management of chronic pancreatitis. In: Bhutani MS, Tandon RK, editors. Advances in gastrointestinal endoscopy. 1st ed. New Delhi: Jaypee Brothers Medical Publishers; 2001. p. 284-302. 9. Bhasin DK, Sriram PVJ, Nagi B, Varma V, Singh K. Endoscopic stenting of minor papilla for symptomatic pancreatic divisum. Indian J Gastroenterol 1997;16:30-1. 10. Bhasin DK, Dhavan S, Sriram PVJ, Nagi B, Varma V, Singh G, et al. Endoscopic management of pancreatic diseases. Indian J Gastroenterol 1997;16:151-2. 11. Buchler M, Friess H, Bittner R, Roscher R, Krautzberger W, Muller M, et al. Duodenum preserving pancreatic head resection: Long-term results. J Gastrointest Surg 1997;1:13-7. 12. Nealon WH, Thompson JC. Progressive loss of pancreatic function in chronic pancreatitis is delayed by main duct decompression. Ann Surg 1993;217:458-68.
13. Sidhu SS, Nundy S, Tandon RK. The effect of the modified Puestow procedure on diabetes in patients with tropical chronic pancreatitis: a positive study. Am J Gastroenterol 2001;96:107-11. 14. Sato T, Miyashita E, Yamauchi H, Matsuno S. The role of surgical treatment for chronic pancreatitis. Ann Surg 1986; 203:266-71. 15. Adamek HE, Jakobs R, Buttmann A, Adamek MU, Schneider ARJ, Riemann JF. Long term follow up of patients with chronic pancreatitis and pancreatic stones treated with extracorporeal shock wave lithotripsy. Gut 1999;45:402-6. 16. Ammann RW, Akovbiantz A, Largiader F, Scheueler G. Course and outcome of chronic pancreatitis. Longitudinal study of a mixed medical-surgical series of 245 patients. Gastroenterology 1984;86:820-7.
EMR of ileal adenoma: report of two cases Kenji Tsuchida, MD, Naotsuka Okayama, MD, Yoshifumi Yokoyama, MD, Takashi Joh, MD, Kyoji Seno, MD, Hirotaka Ohara, MD, Makoto Sasaki, MD, Hiromi Kataoka, MD, Fuminori Okumura, MD, Makoto Itoh, MD
Various types of malignant tumor, such as lymphoma and carcinoma, arise in the terminal ileum,1 but adenoma is rare in this segment of the small intestine. Two cases are reported in which an adenoma in the terminal ileum was removed by EMR. Endoscopic and stereomicroscopic findings are presented. The clinical benefit of EMR for ileal adenoma is discussed. CASE REPORT Case 1 A 65-year-old man presented with hematochezia. There was a history of laparotomy 24 years earlier for duodenal ulcer. The family history was unremarkable. At a prior colonoscopy, 5 colonic polyps and one ileal polyp were found, and the patient was referred for further evaluation and treatment. The abdomen was soft and flat, a surgical scar was present, and there was no tenderness or palpable mass. Laboratory data included an alkaline phosphatase of 274 U/L (normal: 60-230 U/L) and carcinoembryonic antigen level of 9.3 ng/mL (<5 ng/mL). Colonoscopy revealed a slightly white, flat-elevated 7mm tumor with a central depression and slightly irregular Current affiliations: Internal Medicine, Nagoya City Johsai Hospital, Nagoya City University Graduate School of Medical Sciences, Department of Internal Medicine and Bioregulation, Nagoya, Japan. Reprint requests: Kenji Tsuchida, MD, PhD, Internal Medicine, Nagoya City Johsai Hospital, 4-1 Kitabata-cho, Nakamura-ku, Nagoya 453-0815, Japan. Copyright Ó 2004 by the American Society for Gastrointestinal Endoscopy 0016-5107/$30.00 PII: S0016-5107(03)02820-7 VOLUME 59, NO. 3, 2004
Figure 1. A, Endoscopic view, showing ileal adenoma (Case 1). B, Chromoendoscopic view of ileal adenoma. surface in the ileum 8 cm from the ileocecal valve (Fig. 1A). Chromoscopy (0.08% indigo carmine) demonstrated irregularity of the tumor surface (Fig. 1B). There seemed to be no invasion into the submucosal layer, because probing with a forceps disclosed that the lesion was mobile. Biopsy specimens revealed the tumor to be an adenoma. Barium GASTROINTESTINAL ENDOSCOPY
443
K Tsuchida, N Okayama, Y Yokoyama, et al.
EMR of ileal adenoma
Figure 4. Photomicrograph of resection specimen (Case 1) (H&E, orig. mag. 3 5).
Figure 2. Barium-contrast radiograph, showing ileal tumor (arrow) (Case 1).
colonoscope. By using a needle forceps (NM-4U; Olympus Optical Co., Ltd., Tokyo, Japan), 3 mL of saline solution were injected into the submucosa at the orad side of the tumor until it was completely elevated. The top half of the elevated mucosa, including the entire tumor, then was resected electrosurgically by using a hexagonal snare (SD6U; Olympus), a generator setting of 3 (PSD-10 generator; Olympus), and cutting current. Residual colonic polyps, all adenomas, also were resected. No complication was encountered during the endoscopic treatment or at 5 years’ follow-up. The EMR specimen (17 3 14 mm) was stained with Mayers-hematoxylin for 30 seconds and washed with water. The mucosal surface then was observed by using a stereomicroscope (SMZ-U ZOOM 1:10; Nikon, Tokyo, Japan). This revealed an abnormal pit pattern (Fig. 3) that was slightly branched but not markedly irregular, suggesting an adenoma instead of carcinoma. The mucosa around the tumor was normal in appearance. Histopathologic examination demonstrated an adenoma with moderate dysplasia that was confined to the mucosal layer (Fig. 4). The margins were free of tumor, and there was no invasion of veins or lymph vessels. Barium-contrast radiography of the small bowel 11 days after EMR revealed no stenosis of the terminal ileum. The patient remains well at 5 years after EMR. Case 2
Figure 3. Stereomicroscopic view of resection specimen (arrowheads) (Case 1) (Mayers-hematoxylin, orig. mag. 3 1.3). contrast radiography also demonstrated the lesion as being round and polypoid (Fig. 2). The source of the hematochezia was a hemorrhoid. Based on the results of the examinations, a decision was made to treat the lesion by EMR. Informed consent was obtained. EMR was performed with a standard video444
GASTROINTESTINAL ENDOSCOPY
A 65-year-old man was referred when colonoscopy, performed as a surveillance examination for colonic polyps, revealed an elevated tumor in the ileum 2 cm from the ileocecal valve. Two adenomas had been removed colonoscopically from the colon 1 year earlier. He also had undergone chemotherapy for an axillary rhabdomyosarcoma 3 years previously. Family history was unremarkable. The abdomen was soft, non-tender, and there was no mass palpable. There was no evidence of recurrence of the axillary tumor. Standard laboratory test results were within normal ranges. VOLUME 59, NO. 3, 2004
EMR of ileal adenoma
K Tsuchida, N Okayama, Y Yokoyama, et al.
Figure 6. Photomicrograph of resection specimen (Case 2) (H&E, orig. mag. 34). Figure 5. Endoscopic view, showing ileal tumor (Case 2).
Colonoscopy revealed a semipedunculated tumor with a slightly irregular surface and focal red spots in the terminal ileum (Fig. 5). The lesion moved in response to probing with a forceps and did not seem to invade the submucosa. After informed consent was obtained, the tumor was completely resected by EMR, without complication. The tumor (6 3 5 3 5 mm) was, by histopathologic evaluation, a tubulovillous adenoma with moderate dysplasia (Fig. 6). At 16 months’ follow-up, there was no stenosis at the EMR site. The patient remains well at 5 years after EMR.
DISCUSSION Adenoma in the small intestine is rare. Many of these benign tumors of the small bowel do not cause symptoms and are discovered only incidentally at autopsy.1 However, O’Brien2 noted, in 1973, that benign tumors in the small bowel were being found more frequently because of more aggressive examination of the ileocecal area. In fact, 7 cases of ileal adenoma have been reported in Japan,3-9 and all of these lesions, including those in the present two cases, were detected by screening colonoscopy or barium-contrast radiography. Three of the 9 patients were asymptomatic, and the lesions were less than 1 cm in size. These observations suggest that ileal adenoma may be more common than is appreciated. Machella1 noted that adenoma was the most common benign tumor found in the ileum incidentally at autopsy. As in the two cases presented, examination of the terminal ileum at screening colonoscopy may occasionally reveal an adenoma. The endoscopic appearance of submucosa-invasive ileal cancer includes irregular nodules with friability and converging mucosal folds.10,11 In our first patient, chromoscopy clearly revealed the granular surface of the tumor, but no erosion or bleeding was VOLUME 59, NO. 3, 2004
observed. The endoscopic findings may be important for distinguishing cancer from adenoma. A case of ileal adenoma with high-grade dysplasia involving an ileocecal valve was previously described by us.12 Stereomicroscopic examination of the tumor surface in that case demonstrated a gyrus-like or branched pit pattern with irregularity, suggesting high-grade dysplasia or carcinoma. In contrast, the lesion in the first case reported did not have an irregular mucosal pit pattern, a finding that suggested adenoma. The lesion proved to be an adenoma with moderate dysplasia. Thus, an irregular surface pit pattern also may distinguish cancer from adenoma. Five of 43 jejunal and ileal adenocarcinomas (about 12%) apparently originated from adenomatous lesions in the study of Bridge and Perzin13 Although the frequency of malignant change in benign tumors of the small intestine has not been established definitively, it is estimated from available data that about 7% of adenomatous polyps become malignant.1 Perzin and Bridge14 suggested that all adenomas of the small intestine be resected, because many adenocarcinomas of the small bowel arise in pre-existing adenomas. Based on these data, it is presumed that excision of ileal adenomas is beneficial by preventing progression to cancer. Many ileal cancers still are discovered when in an advanced stage, in which case the prognosis and 5-year survival rate for patients is extremely poor.15 However, with greater awareness, it is possible that more ileal cancers will be diagnosed when in an early stage, thereby improving overall survival.15 Bridge and Perzin13 found that the prognosis for patients with primary jejunal or ileal carcinoma correlated with depth of tumor invasion, lymph node metastasis, and tumor size. Two of their patients with GASTROINTESTINAL ENDOSCOPY
445
K Tsuchida, N Okayama, Y Yokoyama, et al.
neoplasms that invaded only into the submucosa appeared to be cured. There are 6 cases reported from Japan of ileal cancer that was found in an early stage (two intramucosal, 4 submucosal invasion).10,11,16-18 The patients with these cancers, which were located within 10 cm of the ileocecal valve, were cured by conventional surgery. There was no lymph node metastasis in any patient. These results suggest that early detection and surgical treatment of ileal cancer can improve the prognosis for patients. EMR has been used to treat high-grade dysplasia or intramucosal carcinoma of esophagus, stomach, duodenum, and colorectum, including on the ileocecal valve.12 Tada et al.19 reported that polypectomy for polyps of the small intestine had not been performed before 1982 because of the technical difficulties associated with endoscopy of the small intestine. Polypectomy in the small bowel also was considered to be associated with a high risk of perforation, because the small intestinal wall is relatively thin.19 However, after demonstrating that the small intestinal wall was resistant to electrosurgical perforation in animal experiments, Tada et al.19 suggested that electrosurgical removal of small bowel polyps by polypectomy is safe when performed by a skilled endoscopist. Generally, EMR of small elevated lesions is technically easy. Because many small intestinal adenomas reportedly are pedunculated or semipedunculated,20 it is thought that these lesions can be easily removed by EMR. The adenomas in the two cases presented were semipedunculated and flat-elevated lesions, and EMR was successful with no complication because the tumors were smaller than 1 cm. The most important aspect of the EMR procedure is injection of a sufficient volume of saline solution into the submucosa to elevate the lesion completely, in which case, the entire tumor can be resected without injury to the muscle layer.21 ACKNOWLEDGMENTS We thank Dr. Takaaki Nakamura of the Pathology Department of Kainan Hospital, Aichi, Japan, for his assistance with the histopathologic findings for the resected tumors. REFERENCES 1. Machella TE. Tumor of the small intestine. In: Bockus HL, ed. Gastroenterology. Vol. 2. 2nd ed. Philadelphia: Saunders; 1964. p. 176-204. 2. O’Brien TF Jr. Primary tumors and vascular malformations. Philadelphia: Saunders; 1973. p. 959-70. 3. Matsumoto K, Matsumoto K, Takeuchi K, Matsumoto K, Nakayama O, Kitagawa T, et al. Ileal adenomas diagnosed preoperatively by endoscopic examination after desintussception [in Japanese with English abstract]. Gastroenterol Endosc 1986;28:1627-32. 446
GASTROINTESTINAL ENDOSCOPY
EMR of ileal adenoma
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