Results of the interim analysis of a prospective, multicenter, observational study of small subepithelial lesions in the stomach.

OBJECTIVES: Long-term outcomes of gastric subepithelial lesions have not been elucidated. To reveal the natural history, we initiated a prospective, 10-year follow-up of patients with small (≤20 mm) gastric subepithelial lesions in September 2014. Here, we report the results of an interim analysis of a prospective observational study. METHODS: In total, 567 patients with 610 lesions were prospectively registered between September 2014 and August 2016. The location, size, morphology, and number of subepithelial lesions were recorded on a web-based case report form. This study has been conducted as an Academic Committee Working Group of the Japan Gastroenterological Endoscopy Society. RESULTS: The endoscopic follow-up period was 4.60 ± 1.73 years (mean ± standard deviation), and survival data were investigated for 5.28 ± 1.68 years. This interim analysis revealed that the estimated cumulative incidence of a size increase ≥5 mm, after accounting for patients' death and resection of the tumor as competing risk events, was 4.5% at 5 years. In addition, the estimated cumulative incidence of lesion size increase ≥5 mm or resection of lesions was 7.9% at 5 years, and that of size increase ≥10 mm or resection of lesions was 4.5% at 5 years. CONCLUSION: These results indicate that approximately one in 13 patients with small (≤20 mm) gastric subepithelial lesions may require resection or further investigation for increased tumor size (≥5 mm) within 5 years.

Current Challenge: Endoscopic Submucosal Dissection of Superficial Non-ampullary Duodenal Epithelial Tumors.

OPINION STATEMENT: With the widespread use of esophagogastroduodenoscopy in recent years, the detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) is increasing. Most SNADETs are early-stage adenocarcinoma or benign conditions, including adenoma. Therefore, endoscopic resection is desirable from the perspective of quality of life. However, endoscopic resection for SNADETs has not yet been established. Endoscopic submucosal dissection (ESD) is the most promising method for the treatment of SNADETs, because ESD provides a high rate of en bloc resection and a low rate of recurrence regardless of the tumor size. However, the difficulty of the procedure and a high rate of severe adverse events including perforation and bleeding have become major problems. Various preventive countermeasures for adverse events, such as use of specific devices, endoscope stabilization methods, and endoscopic closure of the post-ESD ulcer using clips, are reported to reduce the risk of the adverse events of ESD for SNADETs. This article reviews and highlights the current state of ESD for SNADETs and new challenges towards safe and effective ESD.

Endoscopic resection using the Clutch Cutter and a detachable snare for large pedunculated colonic polyps.

Background and study aims Endoscopic snare polypectomy with prophylactic detachable snare of large pedunculated colonic polyps (PCPs) is technically demanding. To facilitate removal of such polyps, we developed endoscopic resection using the Clutch Cutter and a detachable snare (ERCCDS). This study aimed to evaluate the efficacy and safety of the procedure. Patients and methods From April 2010 to July 2015, 14 consecutive patients who had PCPs with head > 10 mm, stalk width > 5 mm, and stalk length > 10 mm were enrolled in this single-center prospective uncontrolled study. They were treated using ERCCDS by a single endoscopist. The efficacy and safety were assessed using a database prospectively formatted from the medical records. Results The Clutch Cutter was able to cut the distal side of the stalk an adequate distance from the detachable snare under good visual control. R0 resections were obtained in all lesions. There were no immediate or delayed complications. Conclusions ERCCDS appears to be a safe, easy, and technically efficient method for large PCPs, although larger studies are needed to compare ERCCDS and standard resection.

Short- and long-term outcomes of endoscopic resection of rectal neuroendocrine tumours: analyses according to the WHO 2010 classification.

OBJECTIVE: Although the World Health Organisation (WHO) defined a novel classification of gastroenteropancreatic neuroendocrine tumours (NETs) in 2010, indications for endoscopic resection of rectal NETs in the guidelines were based on evidence accumulated for carcinoid tumours defined by a previous classification. This study was designed to clarify indications for endoscopic resection of rectal NETs corresponding to the new WHO classifications. MATERIAL AND METHODS: One hundred-seventy rectal NETs resected endoscopically from April 2001 to March 2012 were histologically re-classified according to the WHO 2010 criteria. The clinicopathological features of these lesions were analysed, and the short- and long-term outcomes of endoscopic resection were evaluated. RESULTS: Of the 170 rectal NETs, 166 were histopathologically diagnosed as NET G1 and four as NET G2. Thirty-eight tumours (22.4%) were positive for lymphovascular invasion, a percentage higher than expected. Although the curative resection rate was low (65.3%), en bloc (98.8%) and complete (85.9%) resection rates were high. Modified endoscopic mucosal resection (88.0%) and endoscopic submucosal dissection (92.2%) resulted in significantly higher complete resection rates than conventional endoscopic mucosal resection (36.4%). No patient experienced tumour recurrence, despite the low curative resection rate. CONCLUSION: Despite the low curative resection rate, prognosis after endoscopic resection of rectal NETs was excellent. Prospective large-scale, long-term studies are required to determine whether NET G2 and tumours >1 cm should be included in the indication for endoscopic resection and whether tumours with lymphovascular invasion can be followed up without additional surgery.

Suitability of the expanded indication criteria for the treatment of early gastric cancer by endoscopic submucosal dissection: Japanese multicenter large-scale retrospective analysis of short- and long-term outcomes.

OBJECTIVE: The criteria for endoscopic resection for early gastric cancer include absolute and expanded indications. Consensus already exists for the absolute indications. However, the suitability of the expanded indications must be validated by long-term outcome analyses since such lesions have only recently become resectable with the development of endoscopic submucosal dissection. The aim of this study is to clarify the suitability of the expanded indications for the treatment of early gastric cancer with endoscopic submucosal dissection. MATERIALS AND METHODS: The medical records of 1161 patients with early gastric cancers (1332 lesions) treated by endoscopic submucosal dissection and meeting the criteria for absolute or expanded indications without additional treatment with gastrectomy were divided into absolute indication group or expanded indication group. RESULTS: Complete resection rates were 96.4% and 93.4% in absolute and expanded indication groups, respectively, with no significant differences between the groups. Delayed bleeding rates were significantly higher in the expanded indication group, whereas all cases were successfully managed conservatively. The 5-year overall survival and recurrence-free rates were 93.7%/99.77% and 90.49%/98.90% in the absolute and the expanded indication groups, respectively, with no significant differences between the groups for either measure. Multivariate analyses revealed that affected horizontal margin and tumor location were independent predictive factors for recurrence. CONCLUSION: The expanded indication group showed excellent post-endoscopic submucosal dissection short-term and long-term outcomes compared with the absolute indications group, demonstrating that expanded indications are suitable for endoscopic submucosal dissection for early gastric cancer.

Gastric Hyperplastic Polyp with Xanthoma Observed by Magnification Narrow-Band Imaging Endoscopy and Endoscopic Ultrasonography : Report of a Case.

We experienced an extremely rare case of gastric hyperplastic polyp with xanthoma. A 73-year-old Japanese man was transferred to our hospital from a referral hospital for further evaluation of a pedunculated gastric polyp and early gastric cancer. Esophagogastroduodenoscopy (EGD) revealed a yellow-whitish pedunculated polyp arising from the anterior wall of the fornix. Magnification narrow-band imaging (NBI) endoscopy revealed extended and tortuous microcapillaries and a swollen interfoveolar pattern on the polyp's surface, but there was no sign of malignancy. Endoscopic ultrasonography (EUS) revealed an irregularity of the first layer and a thickened second layer. The third layer was intact. A hyperechoic area was seen in the thickened second layer. Endoscopic submucosal dissection (ESD) for early carcinoma of the antrum and endoscopic mucosal resection (EMR) for a polyp in the fornix were performed in one session. Histological examination of the specimen of the fornix polyp revealed lengthened, branched and dilatated gastric foveolae and a tight sheet of foamy histiocytes in the stroma. The background mucosa of the polyp was atrophic. The pathologic evidence was gastric hyperplastic polyp with proliferation of xanthoma. The early cancer of the antrum was intramucosal tubular adenocarcinoma and was resected curatively.

Large area of walled-off pancreatic necrosis successfully treated by endoscopic necrosectomy using a grasping-type scissors forceps.

Endoscopic necrosectomy (EN) for walled-off pancreatic necrosis (WOPN) is less invasive than surgical treatment and has become the first choice for pancreatic abscess. EN is usually carried out with several devices including snares, baskets, and grasping forceps. Occasionally, we have encountered cases in which EN has not been satisfactorily carried out, and there is pressure for further innovation in EN. Here, we describe a case of a large area of WOPN that was successfully treated by EN with endoscopic submucosal dissection and associated techniques, which facilitated removal of necrotic tissues. A 60-year-old man was referred to our hospital for WOPN as a complication of necrotizing pancreatitis. As a result of his complicating conditions including ischemic heart disease, uncontrollable arrhythmia, chronic renal failure, and persistent pleural effusion, he was deemed a poor surgical candidate. Although EN with conventional devices was carried out for five sessions, we could not remove the dense and massive necrotic tissues. At the sixth EN session, the Clutch Cutter device (Fujifilm, Tokyo, Japan) was used to remove the necrotic tissues, without major complications. This is believed to be the first report of EN using the Clutch Cutter for successful treatment of WOPN.

Gastric glomus tumor diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy: report of a case.

A glomus tumor of the stomach is rare. It is difficult to diagnose the tumor before surgery by only endoscopic biopsy and radiography, and there is no established method of diagnosis before surgical treatment. Esophagogastroduodenoscopy (EGD) on a 50-year-old Japanese woman revealed a 10 mm submucosal tumor in the anterior wall of the gastric angle. Follow-up EGD revealed an increase in the size of the tumor to 15mm. Endoscopic ultrasonography (EUS) demonstrated a 15mm subepithelial hypoechoic solid tumor with continuity to the proper muscle layer. Histologic diagnosis by endoscopic ultrasonography guided fine needle aspiration (EUS-FNA) was glomus tumor. The tumor was treated by laparoscopic local resection. The histologic diagnosis of the resected tumor was similar to the preoperative EUS-FNA results. EUS-FNA would appear to be an effective histologic test for early diagnosis of gastric glomus tumor.

Efficacy and histologic frequencies of endoscopic ultrasonography-guided tissue acquisition using conventional fine-needle aspiration needles for gastric subepithelial hypoechoic mass.

Introduction/Purpose: For gastric subepithelial lesions (GSELs) showing a hypoechoic mass (HM) on endoscopic ultrasonography (EUS) imaging, the utility of EUS-guided tissue acquisition using conventional fine-needle aspiration needles (EUS-TA-CFNAN) and the frequency of histological types remain unclear. This study aimed to examine this issue. Methods: This prospective observational study enrolled 291 consecutive patients who underwent EUS-TA-CFNAN for GSELs showing an HM (GSELHM) on EUS imaging. Immunohistochemical analysis was performed for all EUS-TA-CFNAN and surgically resected specimens. The main outcome measures were the technical results of EUS-TA-CFNAN and the frequency of histological types in GSELHM. Results: The endoscopic ultrasound-guided tissue acquisition using conventional fine-needle aspiration needle diagnosis rate for GSELHM was 80.1% (95% confidence interval [CI]: 75.0-84.5, 233/291). It was significantly lower for antrum (P = 0.004) and lesions smaller than 2 cm (P = 0.003). There were no adverse events. The immunohistochemical diagnoses of EUS-TA-CFNAN included 149 cases of gastrointestinal stromal tumour (GIST) (51.2%), 48 cases of leiomyoma (16.5%), 11 cases of schwannoma (3.8%), 8 cases of the ectopic pancreas (2.7%), 5 cases of subepithelial lesion like cancer (1.7%), 12 cases of other lesions (4.1%), and 58 cases of undiagnosable lesions (19.9%). The frequency of malignant or potentially malignant tumour in GSELHM was 55.0% (95% CI: 49.1-60.8, 160/291). Surgery was performed in 149 patients according to the conclusive EUS-TA-CFNAN results, in which the diagnostic accuracy of EUS-TA-CFNAN was 97.3% (95% CI: 94.7-99.9, 145/149). Conclusion: The use of EUS-TA-CFNAN for GSELHMs is safe and accurate. Gastric subepithelial lesions showing a hypoechoic mass have a reasonably high possibility of containing malignant or potentially malignant tumours, including GISTs.

Endoscopic submucosal dissection using the "Clutch Cutter" for early esophageal squamous cell carcinoma.

BACKGROUND AND STUDY AIMS: To reduce the risk of complications related to the use of knives in endoscopic submucosal dissection (ESD), we developed the Clutch Cutter which can grasp and incise targeted tissue using electrosurgical current, similarly to a biopsy technique. The study aim was to evaluate the efficacy and safety of ESD using the Clutch Cutter for early esophageal squamous cell carcinoma. PATIENTS AND METHODS: ESD using the Clutch Cutter was performed on 32 consecutive patients with early esophageal squamous cell carcinoma. Therapeutic efficacy and safety were assessed. RESULTS: All lesions were treated easily and safely without unintended incision. En bloc resection was obtained in all patients. Histologically negative margins were obtained in 26/32 patients (81%). Endoscopic perforation due to the hood in one patient (3%), mediastinitis without endoscopic perforation in one patient (3%), and post-ESD stricture in 5 patients (16%) were observed. All were successfully managed conservatively. CONCLUSIONS: ESD using the Clutch Cutter appears to be a safe, easy, and technically efficient method for resecting early esophageal squamous cell carcinomas.

Preserved gastric motility in patients with early gastric cancer after endoscopic submucosal dissection.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) is now accepted as a minimally invasive treatment for early gastric cancer (EGC). To our knowledge, however, the functional effects of ESD have not been determined in patients with EGC. We therefore investigated whether gastric motility was affected by ESD. METHODS: Using the (13) C-octanoic acid breath test, gastric emptying of solid test meals was examined in 26 EGC patients and 18 healthy controls, with EGC patients assayed before and about 2 months after ESD. Based on (13) CO2 breath-excretion curves, the lag-phase time (T(lag) ), half-emptying time (T(1/2) ), and gastric emptying coefficient (GEC) were calculated as indices of gastric emptying. RESULTS: In healthy controls, the mean T(lag), T(1/2), and GEC were 85.5 ± 4.9 min, 148.5 ± 8.0 min, and 3.01 ± 0.09 h, respectively. Before ESD, the mean T(lag) , T(1/2), and GEC in the EGC patients were 90.1 ± 5.5 min, 174.7 ± 10.4 min, 2.64 ± 0.08 h, respectively. GEC, but not T(lag) or T(1/2), differed significantly in the two groups, with gastric emptying slower in EGC patients than in controls. Relative to before ESD, the mean T(lag), T(1/2), and GEC in EGC patients after ESD were 109.2% ± 7.8%, 107.9% ± 9.6%, 108.4% ± 4.7%, respectively, indicating that ESD did not significantly affect any of these gastric emptying parameters in EGC patients. CONCLUSION: ESD is an effective treatment for EGC both in preserving organs and gastric motility.

Prospective, randomized, double-blind, placebo-controlled trial of ulinastatin for prevention of hyperenzymemia after double balloon endoscopy via the antegrade approach.

BACKGROUND: Double balloon endoscopy (DBE) allows the entire small intestine to be viewed using a combination of antegrade and retrograde approaches. Acute pancreatitis is a serious complication of antegrade DBE with no effective prophylactic treatment currently available. Ulinastatin has been shown to be effective for the prevention of pancreatitis following endoscopic retrograde cholangiopancreatography. We therefore assessed the efficacy of ulinastatin for hyperenzymemia after antegrade DBE. PATIENTS AND METHODS: Forty-four patients were enrolled in this prospective, randomized, double-blind, placebo-controlled trial. Patients in the ulinastatin group received 150 000 U ulinastatin by i.v. drip infusion for 2 h from the start of the procedure. Serum concentrations of pancreatic amylase and lipase were measured before and 3 and 18 h after antegrade DBE. RESULTS: The study was terminated after interim analysis. Of the 44 patients, 23 were randomized to ulinastatin and 21 to placebo.The groups were similar with regard to sex ratio, age, type of endoscope, insertion time, total procedure time, number of endoscope pull-back procedures, and baseline pancreaticamylase and lipase concentrations. Post-DBE hyperenzymemia was observed in 35.0% and 47.8% of patients in the placebo and ulinastatin groups, respectively. The higher frequency of hyperenzymemia in the ulinastatin group was unexpected, but the difference was not statistically significant. One patient in the placebo group (5.0%) and none in the ulinastatin group experienced acute pancreatitis, but the difference was not statistically significant. CONCLUSION: The results of this trial suggest that ulinastatin does not prevent hyperenzymemia following antegrade DBE.

Endoscopic Ultrasonography-Guided Fine-Needle Aspiration for Duodenal Subepithelial Lesions Showing a Hypoechoic Mass on Endoscopic Ultrasound Imaging.

BACKGROUND/AIMS: For duodenal subepithelial lesions showing a hypoechoic mass on endoscopic ultrasound imaging, the utility of endoscopic ultrasound-guided fine-needle aspiration and the frequency of histological types have not been the focus of previous literature. This study aimed to clarify this. MATERIALS AND METHODS: This prospective observational study enrolled 22 consecutive patients who underwent endoscopic ultrasoundguided fine-needle aspiration for duodenal subepithelial lesions with hypoechoic mass on endoscopic ultrasound. Immunohistochemical analysis was performed for all endoscopic ultrasound-guided fine-needle aspiration and surgically resected specimens. The main outcome measures were the technical results of endoscopic ultrasound-guided fine-needle aspiration and the frequency of histological types of duodenal subepithelial lesions with hypoechoic mass. RESULTS: Thirteen fine-needle aspiration specimens were obtained from the duodenal bulb and eight from the descending duodenal region. The puncture was not performed because of intervening vessels in one patient. The diagnostic rate was 81% (95% confidence interval: 58.1-94.6, 17/21 patients). In 12 patients receiving surgical resection (excluding one cancellation of endoscopic ultrasoundguided fine-needle aspiration), the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration was 75% (95% confidence interval: 42.8-94.5, 9/12 patients). No complications were observed. The histopathological diagnoses included 11 cases of gastrointestinal stromal tumor (50%), 2 cases of leiomyoma (9%), 2 cases of metastatic cancer (9%), 2 cases of benign inconclusive, and 1 case each of carcinoid, malignant lymphoma, leiomyosarcoma, gauzeoma, and aberrant pancreas (4.5% each). The frequency of malignant tumors in the duodenal subepithelial lesions with hypoechoic mass group was 73% (16/22 patients). CONCLUSIONS: Endoscopic ultrasound-guided fine-needle aspiration for duodenal subepithelial lesions with hypoechoic mass was safe and accurate. As duodenal subepithelial lesion with hypoechoic mass has a reasonably high possibility of containing malignant tumors, it is desirable to perform endoscopic ultrasound-guided fine-needle aspiration.

Adenocarcinoma arising in an intramural diverticulum presenting as a long-standing submucosal tumor.

We report a rare case of adenocarcinoma arising in a gastric partial diverticulum in the upper portion of the stomach. The lesion had been followed up for approximately 14 years as a gastric submucosal tumor. However, a recent regular check-up revealed mucous material with some neoplastic tissue discharged from the top of the lesion. A surgically resected specimen showed a well-demarcated submucosal lesion identical to a pseudo-diverticulum carrying a distinctive intramucosal minimally invasive adenocarcinoma in part, with surrounding non-neoplastic but hyperplastic mucosal components. Intestinal phenotype, along with gastric foveolar, pyloric gland-type phenotypes, and neoplastic cells with neuroendocrine differentiation, were also identified in the adenocarcinoma. Chronic and persistent irritation within the diverticulum was postulated to be implicated in the carcinogenesis of the lesion, which carried no definite Helicobacter pylori microorganisms. We believe it is crucial not to overlook carcinoma in a diverticulum presenting as a long-standing submucosal tumor.

A new approach: endoscopic submucosal dissection using the Clutch Cutter® for early stage digestive tract tumors.

Endoscopic submucosal dissection (ESD) is accepted as minimally invasive therapy for early stage digestive tract tumors. It has allowed the achievement of histologically curative en-bloc resection of early stage digestive tract tumors regardless of size, including the resection of previously non-resectable tumors. Although numerous electrosurgical knives have been developed for ESD, technical difficulties and high complication rates (bleeding and perforation) have limited their use worldwide. Furthermore, conventional ESD usually needs several devices for each session. We developed the Clutch Cutter® (CC), which can grasp and incise the targeted tissue using electrosurgical current, to resolve such ESD-related problems. The ESD procedure using the CC is as follows: after marking using the CC and the injection of a solution into the submucosa, the lesion is separated from the surrounding normal mucosa by complete incision around the lesion using the CC. A piece of submucosal tissue is grasped and cut with the CC using electrosurgical current to achieve submucosal exfoliation. Intraoperative bleeding is also treated by the CC. Reported clinical studies showed that ESD using the CC is a safe, simple, easy-to-learn, technically efficient (en-bloc resection rate 100%), and a single-device method for the dissection of early stage digestive tract tumors. This new approach is promising to become the worldwide method of choice for early stage digestive tract tumors because it is technically simple and safe to perform.

Endoscopic submucosal dissection using a grasping-type scissors forceps for early gastric cancers and adenomas.

AIM: To reduce the risk of complications related to endoscopic submucosal dissection (ESD) using knives, we developed a new grasping-type scissors forceps (GSF) that can grasp and incise the target tissue using electrosurgical current. The aim of the present study was to evaluate the efficacy and safety of ESD using GSF for the removal of early gastric cancers and adenomas. METHODS: ESD using GSF was carried out on 35 consecutive patients with early gastric cancers or adenomas who had preoperative EUS diagnoses of mucosal tumor without lymph node involvement. Therapeutic efficacy and safety were assessed. RESULTS: All lesions were treated easily and safely without unexpected incision. The mean size of epithelial tumors and resected specimens was 15.6mm and 32.7mm, respectively. Curative en-bloc resection rates according to tumor size and location were 96% (26/27) in tumors ≤20mm, 100% (8/8) in tumors >20mm, 100% (18/18) of tumors in the lower portion, 100% (8/8) of tumors in the middle portion, 89% (8/9) of tumors in the upper portion, and 97% (34/35) overall. The mean operating time according to tumor size and location was 93.4min in tumors ≤20mm, 140min in tumors >20mm, 77.6min for tumors in the lower portion, 113.4min for tumors in the middle portion, 148.6min for tumors in the upper portion, and 104.1min overall. No intraoperative complication occurred, and postoperative bleeding was seen in 3% (1/35). CONCLUSIONS: ESD using GSF allows simple and safe en-bloc resection of early gastric cancer or adenoma irrespective of tumor size and location.

Is double-balloon colonoscopy a better aid to unskilled colonoscopists than conventional colonoscopy?

BACKGROUND AND STUDY AIMS: To compare the clinical outcome of double-balloon colonoscopy (DBC) with conventional colonoscopy (CC) for colon evaluation performed by an unskilled colonoscopist. PATIENTS AND METHODS: Between June 2008 and November 2008, 1544 colonoscopies were performed in our hospital. Fifty-eight patients, (29 male and 29 female ; 19-86 years; mean age, 63 years) involving 60 intubations, were enrolled in this study and were assigned randomly to the DBC or CC group. One first-year GI fellow was enrolled and performed these 60 consecutive colonoscopies (30 DBCs, 30 CCs). Completion rate of colonoscopy, cecal intubation time, and rate of analgesic agent usage were analyzed. RESULTS: Completion of DBC was 100% (30/30), while completion of CC was 73% (22/30). There was a statistically significant difference (p < 0.05). The mean cecal intubation time was 36.2 +/- 14.4 minutes (DBC) and 36.5 +/- 15.2 minutes (CC). There was no statistically significant difference. Analgesic agent was used with 19 intubations (63%) (DBC) and with 27 intubations (90%) (CC) (p < 0.05). CONCLUSIONS: For inexpert endoscopists, using DBC has a higher rate of effectiveness than using CC and can decrease the discomfort of patients during colonoscopic procedures.

[A case of rectal implantation cyst diagnosed by EUS and EUS-guided FNA].

A 73-year-old woman was referred to our hospital complaining of bloody stool. She had undergone high anterior resection with the double stapling technique for a sigmoid colon cancer 2 years prior to this admission. Colonoscopy revealed a soft submucosal tumor, 4cm in size, on the anal side of the previous anastomosis in the rectum. EUS revealed a cystic lesion located in the third and fourth layers of the rectal wall. EUS-FNA was performed, and the content of the cystic lesion was transparent mucinous liquid. Histologically, the specimen revealed PAS and Alcian blue-positive mucinous material and a small number of inflammatory cells such as foamy macrophages. Therefore, this cystic lesion was diagnosed as a rectal implantation cyst.