Rectal Carcinoid Tumors Research Articles

Endoscopic Submucosal Dissection for Rectal Neuroendocrine (Carcinoid) Tumors

Rectal neuroendocrine (carcinoid) tumors smaller than 1 cm without lymph node metastasis and confined within the submucosal layer (stage T1aN0) can be treated using endoscopic resection. The present study was aimed to assess the safety and efficacy of endoscopic submucosal dissection (ESD) for T1aN0 carcinoid tumors. A total of 35 consecutive patients with a T1aN0 rectal carcinoid tumor were enrolled between March 2007 and December 2009. The study evaluated the histologically complete resection rate, procedure time, complications, and short-term oncological outcomes. The mean patient age was 49.0 years (range, 32-74 years), and there were 25 men and 10 women. The mean procedure time was 35.6 minutes (range, 7-82 minutes). All neoplasms were removed in one piece, and the histologically complete resection rate was 74.3% (26 cases including 5 cases showing no residual tumor). No post-ESD bleeding was observed. Abdominal computed tomography scans showed a perforation in 1 patient only, but that perforation was not associated with any peritonitis symptoms, and the patient was discharged on postprocedure day 3. One patient underwent radical surgery after ESD because of angiolymphatic invasion and positive resection margins, and the final pathology revealed no residual tumor or lymph node metastasis. No patient showed local recurrence or distant metastasis during a median follow-up of 25 months (range, 12-43 months). ESD is feasible and safe for treating T1aN0 rectal carcinoid tumors. Further studies are required to accurately determine long-term oncological outcomes.

Prevalence of Rectal Carcinoid Tumors Among Outpatient Colonoscopy Patients and the Utility of Immunohistochemistry for Definitive Diagnosis

Prevalence of Rectal Carcinoid Tumors Among Outpatient Colonoscopy Patients and the Utility of Immunohistochemistry for Definitive Diagnosis

Su1537 Feasibility of Endoscopic Treatment for Rectal Carcinoid Tumors According to Tumor Size

Feasibility of Endoscopic Treatment for Rectal Carcinoid Tumors According to Tumor Size Soung Min Jeon, Jin Ha Lee, Sung Pil Hong, Tae Il Kim, Won Ho Kim, Jae Hee Cheon Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Republic of Korea Background/Aims: This study was aimed to assess whether endoscopic treatment for rectal carcinoid tumors larger than 10 mm is feasible in terms of the rates of en bloc resection, histological complete resection, complication incidence, and tumor recurrence. Methods: Endoscopic treatments including conventional endoscopic mucosal resection (EMR), endoscopic mucosal resection using a cap (EMR-C), and endoscopic submucosal dissection (ESD) were performed to 101 patients among 111 patients diagnosed to have rectal carcinoid tumors at Severance Hospital in Seoul, Korea, between January 2005 and December 2009. All patients were confirmed to have no muscular layer invasion, no metastases to the lymph nodes or distal organs, and no atypical histological features. The patients were categorized into three groups by tumor size; (A) 1 10 mm, (B) 11 15 mm, and (C) 16 20 mm. We retrospectively reviewed their endoscopic pictures/video and medical records, and analyzed differences in results of endoscopic treatment and follow-up among the 3 groups. Results: Among the 3 groups, significant differences in baseline characteristics of patients and tumors were not shown except for tumor size. Although the rates of en bloc resection and pathologic complete resection did not differ according to tumor size, complication incidence and the rates of local recurrence, metastasis, and need for additional rescue therapy were higher as tumor size was larger (complication rate; 8.1%, 21.4%, 46.2%, p 0.001/ recurrence rate; 1.4%, 7.1%, 38.5%, p 0.001/ metastasis rate; 1.4%, 7.1%, 23.1%, p 0.004/ need for rescue therapy; 5.4%, 21.4%, 61.5%, p 0.001, in A, B, and C groups, respectively). In multivariate analysis for the risk factors of additional treatment after endoscopic treatment of rectal carcinoids, method of endoscopic treatment, invasion depth, and en bloc resection were not found to be independent risk factors, but only tumor size was an independent risk factor (RR of 11 20 mm to 1 10 mm in tumor size; 13.098, p 0.008/RR of 16 20 mm to 1 15 mm in tumor size; 20.894, p 0.002). ESD was superior to EMR/EMR-C in terms of rates of endoscopically and pathologically complete resection and complication. However, the procedure time of ESD was longer than EMR/EMR-C and the rate of additional rescue therapy after ESD did not reveal statistical differences compared with EMR/EMRC in all groups. Conclusions: In rectal carcinoid tumors with size 10mm, endoscopic treatment might be most feasible and both EMR/EMR-C and ESD showed similar efficacy and safety. However, surgery is still indicated for rectal carcinoid tumors which are larger than 10 mm because of high risk of need for additional rescue therapy and metastasis.

SPT:直腸カルチノイド腫瘍に対するESDの適性について:EMRとの比較

SPT:直腸カルチノイド腫瘍に対するESDの適性について:EMRとの比較

Feasibility of salvage endoscopic mucosal resection by using a cap for remnant rectal carcinoids after primary EMR

Secondary endoscopic treatment for remnant lesions of rectal carcinoid tumors after primary EMR or polypectomy is technically difficult because of fibrosis of residual tissues. EMR by using a cap (EMR-C), a method to resect the submucosal layer by suction by using a transparent cap, may be feasible as a salvage treatment. To assess the feasibility of salvage EMR-C. Retrospective analysis. Tertiary academic health care system. Thirty-one patients who were referred for salvage treatment of a failed en bloc excision of rectal carcinoid tumors after primary EMR or polypectomy between January 2007 and December 2009. Salvage EMR-C for remnant carcinoid tumors in the rectum. Rate of complete resection, complications, length of procedure, and recurrence rate. The mean age of the patients was 52.0±11.8 years (range 30-78 years). The mean tumor size was 8.9±3.2 mm (range 5.0-13.0 mm). The mean procedure time was 9.1±3.7 minutes, and clear resection margins were pathologically confirmed in all 31 patients. The most common complication of salvage EMR-C was bleeding (7 patients, 22.6%), which was successfully treated by hemoclipping in all cases. The 1-year follow-up colonoscopy and CT results for all patients were negative for recurrence. Retrospective design and limited cases at a single center. EMR-C is a feasible salvage therapeutic option for failed en bloc excision after primary endoscopic treatment of rectal carcinoid tumors.

Clinical experience with neuroendocrine rectal tumors.

611 Background: Carcinoids are heterogeneous neuroendocrine tumors with malignant potential. The rectum is the third most common location for gastrointestinal carcinoids after small bowel and colon. Due to their rarity, the characteristics and behavior of this unusual malignancy remain unclear. Methods: Retrospective review of the clinicopathologic features of patients treated for carcinoid tumors of the rectum. Results: A single institute's tumor registry was retrospectively queried, identifying nine patients with rectal carcinoid tumors over a 10-year period. The mean age at diagnosis was 57.6 years. Four of the nine patients were female. Presenting symptoms included abdominal pain in five patients, rectal bleeding in two patients and a change in bowel habits in one patient. As previously reported, no patient had symptoms consistent with carcinoid syndrome. The rectal tumor size was > 2 cm in five patients. The rectal tumor was located in the lower third of the rectum in three cases (< 5 cm from anal verge) whereas three were in the middle third (6-11 cm) and two in the upper third (11-15 cm). Four of the tumors were well differentiated tumors (grade 1), 1 was atypical carcinoid or moderately differentiated tumors (grade 2), and 4 were poorly differentiated tumors (grade 3) according to the SEER. Initially, 5/9 patients had distant metastasis. As an initial site of metastasis, the liver was the most common site (4/5 patients, 80%). Five patients underwent surgical treatment of their rectal tumor, two with endoscopic transanal resection whereas 3 patients had a low anterior resection (LAR). Three patients received chemotherapy treatment only in the metastatic setting and one patient received chemotherapy and radiotherapy as palliative treatment. Of the nine patients, five had progressive disease after initial treatment. With a median follow-up of 14 months, the overall survival of the entire population was 13.4 months. Conclusions: Neuroendocrine carcinomas of rectum are uncommon. Only small rectal carcinoids can be safely managed and surgery represents the treatment that can offer a greater chance of survival to these patients. Larger primary tumors have a high tendency to spread early. They are associated with aggressive behavior, resistance to chemotherapy and poor prognosis. No significant financial relationships to disclose.

Efficacy of Endoscopic Mucosal Resection after Circumferential Mucosal Incision of Small Rectal Carcinoid Tumors

Background: Endoscopic mucosal resection is widely used for treating rectal carcinoid tumors. However, histopathology has revealed that submucosal invasion leads to incomplete resection. Endoscopic submucosal dissection, which enables en bloc resection regardless of tumor size, has recently been reported to be useful in treating rectal carcinoid tumors; however, it is not widely used as standard treatment because of technical demands. We use endoscopic mucosal resection after circumferential mucosal incision, which is performed after mucosal resection around the lesion to treat rectal carcinoid tumors. To our knowledge, this is the first report of endoscopic mucosal resection after circumferential mucosal incision for colorectal carcinoid tumors. Objective: To evaluate the efficacy of this method. Design: Single-center retrospective clinical trial. Setting: Shiga University of Medical Science. Patients: We retrospectively studied 6 patients with rectal carcinoid tumors ≤ 10 mm treated by endoscopic mucosal resection after circumferential mucosal incision, between August 2010 and December 2012 at Shiga University of Medical Science. Interventions: Endoscopic mucosal resection after circumferential mucosal incision. Main outcome measures: En bloc resection rate, procedure time, complications. Results: The mean tumor size was 6.8 ± 1.8 mm (range 4-9 mm). The mean procedure time was 19.7 ± 5.1 min (range, 12-26 min). The en bloc and complete resection rates were 100% (6/6) and 50% (3/6), respectively. All tumor depths were contained in the submucosa, and clear resection margins were pathologically confirmed in all 6 patients. Three patients with lymphovascular involvement required additional radical surgical therapy. There were no complications or distant/local recurrence during the follow-up period (median, 4 months; range 4-26 months). Limitations: This study was limited by its retrospective nature. Conclusions: Endoscopic mucosal resection after circumferential mucosal incision was effective for treating ≤ 10-mm-diameter rectal carcinoid tumors.

Chronic Ulcerative Colitis Complicated by Rectal Carcinoid Tumor: A Report of Two Cases

潰瘍性大腸炎（ulcerative colitis；以下，UC）長期罹患例にカルチノイドの合併を認めた2症例を経験したので報告する．いずれも全大腸炎型UCに合併した直腸カルチノイドで，長期経過観察中のサーベイランス内視鏡にて下部直腸に径5～10mm大のカルチノイドを認め，経肛門的切除，ESDを施行した．いずれもtypical carcinoid tumorであった．

A case of 9mm rectal carcinoid tumor with multiple liver metastases

A case of 9mm rectal carcinoid tumor with multiple liver metastases

Endoscopic Resection for Rectal Carcinoid Tumor: Efficacy and Clinical Results of Follow-up

Background/Aims: With the growing volume of screening colonoscopies, the incidence of rectal carcinoids and the number of endoscopic resections for rectal carcinoids are also increasing. However, the prognosis including recurrence and metachronous lesions after endoscopic resection is unclear. Methods: The medical records of 255 patients who had undergone endoscopic resection for rectal carcinoids between October 1999 and April 2010 were retrospectively reviewed. Results: The number of males was 150 (58.8%), and the mean age was 54.1 years (range, 27-85 years). Mean tumor size was 6.9 mm. In total, 162 cases (63.5%) were treated with endoscopic mucosal resection and 93 (36.5%) were treated with endoscopic submucosal dissection. Although endoscopic complete resections were achieved in all cases, the histological examination showed 47 cases with a positive resection margin (18.4%) and three with lymphovascular invasion (1.2%). In the 54 patients with a free resection margin, who were followed for more than 12 months, abdominopelvic computed tomography and endoscopy did not show recurrence after a median of 30.5 and 36 months, respectively. Three patients with lymphovascular invasion did not show recurrence during follow-up period of 13, 30, and 37 months, respectively. Metachronous rectal carcinoids were detected in four patients at 23, 58, 61, and 89 months, respectively, after initial endoscopic resection, leading to a second endoscopic treatment. Conclusions: Small rectal carcinoids completely resected grossly and pathologically without lymphovascular invasion appear to have low probability of short-term recurrence. However, considering the slow growth rate of carcinoids, long-term follow-up for recurrence and metachronous carcinoids is required. (Intest Res 2011;9:217-224) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

A Case of Rectal Carcinoid Tumor with Cystic Degeneration

A Case of Rectal Carcinoid Tumor with Cystic Degeneration

Diagnosis and treatment of lymph node metastases of a rectal carcinoid tumor using In111-octreotide-scintigraphy and intraoperative gamma probe detection

Carcinoids represent 1–2% of the rectal cancer. We report the case of a woman with a rectal carcinoid and a hypogastric node metastasis. We propose a less invasive treatment of the metastase using In11-octreotide-scintigraphy and intraoperative gamma-probe detector.

Incidental anorectal pathologic findings in prostatic needle core biopsies: a 13-year experience from a genitourinary pathology consult service

Fragments of anorectal mucosa are frequently present in transrectal prostate core biopsy specimens. Pathologic findings within the anorectal mucosa are easily overlooked, in part because of their rarity and because anorectal mucosa is not the focus of examination. We reviewed pathologic reports of 96,656 prostate biopsies diagnosed in our consultation service from 1997 to 2010. Anorectal lesions were detected in 30 cases, which were summarized as follows: (1) Neoplasia and polyps (n = 10). A flat rectal adenoma with high-grade dysplasia was identified, for which the patient received hemicolectomy. One patient was found to have a rectal carcinoid tumor. Other neoplastic findings included 1 with low-grade B-cell lymphoma, 3 with hyperplastic polyps, 3 with tubular adenomas, and 1 with anal mucosa with high-grade dysplasia that was found to be a contaminant from another case. (2) Inflammatory changes (n = 20). Acute proctitis was found in 12 patients, including 1 with acute radiation proctitis, 2 with inflammatory bowel disease, and 9 with nonspecific proctitis probably due to bowel preparation. Pulse granulomas and nonnecrotizing granulomas were seen in 5 patients, including 3 with diverticular disease, 1 with history of perirectal fistula, and 1 with unknown etiology. Three patients had miscellaneous findings including muciphage reaction, increased eosinophils, and features of collagenous colitis. In conclusion, it is exceedingly rare to find significant pathology in the rectal fragments associated with prostate needle biopsies. Nevertheless, pathologists should evaluate the rectal mucosa for both neoplastic and inflammatory changes to avoid missing clinically significant anorectal diseases.

Selective processing of chromogranin A in rectal carcinoid tumours: An immunohistochemical study with region-specific antibodies

Selective processing of chromogranin A in rectal carcinoid tumours : An immunohistochemical study with region-specific antibodies

The feasibility of endoscopic submucosal dissection for rectal carcinoid tumors: comparison with endoscopic mucosal resection

Rectal carcinoid tumors are often found incidentally during screening colonoscopy and can be resected using various endoscopic techniques. This study aimed to compare the safety and efficacy of endoscopic submucosal dissection (ESD) with endoscopic mucosal resection (EMR) for rectal carcinoid tumors. Between January 2003 and June 2009, 74 patients (74 lesions) underwent either EMR (n = 28) or ESD (n = 46) for rectal carcinoid tumors. The rate of endoscopic complete resection, pathological complete resection, procedure complications, and tumor recurrence were analyzed retrospectively. The endoscopic complete resection rate was significantly higher in the ESD group (46 lesions, 100 %) compared with the EMR group (25 lesions, 89.3 %) ( P = 0.049). The pathological complete resection rate was higher in the ESD group (38 lesions, 82.6 %) compared with the EMR group (18 lesions, 64.3 %); however, this difference was borderline significant ( P = 0.067). Overall complication rate was not significantly different between the EMR group (3.6 %) and the ESD group (6.3 %). There was one case of remnant lesion in the EMR group, which was managed by ESD, and no recurrence has been detected in either the EMR or ESD groups. This study suggests that ESD might be a feasible treatment technique for small rectal carcinoid tumors. It showed superior efficacy and comparable safety to EMR.

Endoscopic mucosal resection for rectal carcinoid tumors

Objective To explore the long-term efficacy of endoscopic sphincterotomy （EST） for choledocholithiasis and to evaluate the necessity of cholecystectomy after EST. Methods Two hundred and fifty seven patients who underwent EST for choledocholithiasis in 2006 were followed up for an average period of 34. 8 months （26-48 months）. According to the existence of cholecystolithiasis, the patients were divided into group A （combined with cholecystolithiasis, n = 151） and group B （without cholecystolithiasis, n = 106） , and group A was further divided into group A1 as undergoing cholecystectomy after EST （n =56） and group A2 as not having cholecystectomy after EST （ n = 95）. Results Of the 257 patients, late complications occurred in 31 patients （12. 1% ） , including recurrent choledocholithiasis in 25 （9.7% ）, cholangitis in 27 （10. 1% ） , acute pancreatitis in 2 （0. 8% ） and cholangiocarcinoma in 1 （0.4% ）. The rates of late complications and recurrent choledocholithiasis were significantly higher in group A2 than those in group A1 （P〈0.05）. Conclusion EST is safe and effective for choledocholithiasis. Cholecystectomy after EST is necessary in patients with cholecystolithiasis. Key words: Carcinoid tumor; Rectum; Endoscopic mucosal resection

Treatment of rectal carcinoid tumors and role of preoperative imaging.

3655 Background: To clarify the optimal management of rectal carcinoid tumors and role of preoperative imaging, retrospective analyses of prospectively accumulated data on treatment results and preoperative imaging were performed. Methods: Prospectively recorded clinicopathologic and imaging data of the 185 consecutive patients with rectal carcinoid tumors undergoing curative intent surgery between 1970 and 2006 were retrospectively analyzed. The recent 37 patients were examined preoperatively by transrectal ultrasonography (TRUS) or high-resolution magnetic resonance imaging (HRMRI). Results: There were 109 men and 76 women with a median age of 57 (range, 24-85) years. The patients were grouped according to tumor size: Group I, < 9 mm; Group II, 9-14 mm; Group III, > 14 mm. The clinicopathologic characteristics and treatment results are shown in the Table. Of the 37 patients examined by TRUS or HRMRI, 9 had invasion of the muscularis propria and 11 had regional lymph node metastasis. Sensitivity and specificity for detection of invasion of the muscularis propria were 100% and 100%, respectively. Sensitivity and specificity for detection of regional lymph node metastasis were 70% and 100%, respectively. Conclusions: Patients with carcinoid tumors measuring less than 9 mm can be treated with ER or LE alone; however, patients with tumors measuring 9 mm or larger should be first examined with TRUS or HRMRI and should be treated with ER or LE or RS according to the TRUS or HRMRI findings. Group No Invasion depth Metastasis Type of surgery 5-yr survival pT1 pT2-3 pN1-2 Liver ER LE RS HR I 120 120 0 0 0 91 20 9 0 100% II 49 44 5 11 1 21 16 12 1 96% III 16 8 8 5 5 3 6 7 5 66% Abbreviations: ER, endoscopic resection; LE, local excision; RS, radical surgery; HR, hepatic resection. No significant financial relationships to disclose.

Endoscopic Submucosal Dissection or Conventional Endoscopic Mucosal Resection Is an Effective and Safe Treatment for Rectal Carcinoid Tumors: A Retrospective Study

Various methods for complete endoscopic resection of rectal carcinoid tumors have been reported. The aim of the present study was to evaluate the clinical usefulness of endoscopic submucosal dissection (ESD) as a new method or conventional endoscopic mucosal resection (EMR) in order to remove rectal carcinoid tumors completely. Between April 2004 and June 2009, 12 patients with rectal carcinoid tumors, estimated at 10 mm, more or less, in diameter, without atypical features and dissected by ESD or resected by EMR, were recruited for this analysis. The complete dissection or resection rate, complications associated with the procedure, local recurrence, and distant metastases were evaluated. Twelve patients were 9 males and 3 females with a mean age of 47.6 years (range, 32-64). The patients had no complaints of carcinoid syndrome symptoms. Tumor size ranged from 5 to 13 mm in diameter, with an average size of 8.8 mm, and 11 of 12 patients (92.7%) had tumors of diameter less than 10 mm. Three of 12 patients (25.0%) were treated by ESD and 9 (75.0%) by conventional EMR. All lesions, including 13-mm-sized carcinoid tumors, were histologically determined to be completely dissected or resected. There were no immediate or late complications (i.e., bleeding or perforation) after ESD or conventional EMR. Histopathologically, there was no tumor invasion beyond the submucosal layer, and all were classified as classical-type carcinoids without lymphovascular invasion. Neither local recurrence nor distant metastasis were detected during a median follow-up period of 28 months. In this study, ESD as a new method or conventional EMR shows promise or potential as a useful, safe procedure to dissect or resect rectal carcinoid tumors of 10 mm, more or less, in diameter. However, long-term outcome remains to be elucidated by a large-scale, prospective study.

PAX8 Expression in Well-differentiated Pancreatic Endocrine Tumors: Correlation With Clinicopathologic Features and Comparison With Gastrointestinal and Pulmonary Carcinoid Tumors

PAX (paired box) genes encode a family of transcription factors that regulate organogenesis and cell-lineage specification in multiple organ systems. In the pancreas, PAX proteins play a critical role in islet cell differentiation. We recently observed that islet cells show strong, diffuse staining for PAX8 by immunohistochemistry. However, PAX8 expression has not previously been examined in pancreatic endocrine tumors (PETs). The purpose of this study was to evaluate PAX8 expression in PETs, and to correlate expression with clinical and pathologic features and behavior. PAX8 expression in other well-differentiated neuroendocrine tumors (WDNETs) was also studied. In total, 190 tumors were evaluated: 156 primary WDNETs (63 PETs, 31 ileal, 5 duodenal, 5 gastric, 19 appendiceal, 13 rectal, and 20 pulmonary carcinoid tumors) and 34 liver metastases (18 PETs and 16 ileal carcinoid tumors). PAX8 was positive in 42/63 (67%) primary PETs. Expression of PAX8 was significantly associated with WHO category 1.1 ("benign" behavior) compared with category 1.2 (uncertain behavior) or 2 (well-differentiated endocrine carcinoma) (positive in 100%, 64%, and 52% of tumors, respectively; P<0.05). PAX8-positive PETs were also significantly smaller and more often clinically functional; PAX8-negative tumors were more frequently associated with liver metastases. PAX8 expression was not associated with patient age, gender, MIB1 index, or lymph node metastases. PAX8 expression was detected in 0/20 (0%) pulmonary, 1/5 (20%) gastric, 5/5 (100%) duodenal, 0/31 (0%) ileal, 4/19 (21%) appendiceal, and 11/13 (85%) rectal carcinoid tumors. Among the liver metastases, PAX8 was positive in 9/18 (50%) metastatic PETs compared with 0/16 (0%) metastatic ileal carcinoid tumors. In summary, PAX8 is expressed in normal pancreatic islet cells and in a high proportion of primary and metastatic PETs. In the GI tract, PAX8 is positive in the majority of duodenal and rectal carcinoid tumors, and in a minor subset of appendiceal and gastric carcinoids. PAX8 expression is absent in ileal and pulmonary carcinoid tumors. PAX8 immunostaining may be helpful in determining the primary site for a WDNET metastatic to the liver, as ileal (PAX8 negative) and pancreatic (PAX8 positive) tumors most often present as a metastasis from an occult primary. PAX8 may also be a prognostic marker in PETs, as loss of expression is associated with malignant behavior.

Endoscopic submucosal dissection for treatment of rectal carcinoid tumors

Conventional EMR has been the endoscopic treatment of choice for rectal carcinoid tumors. However, histologically complete resection often cannot be achieved because the carcinoid tumors are located mainly in the submucosal layer. Endoscopic submucosal dissection (ESD), a new method for large colorectal neoplasm resection, may overcome this problem. To compare ESD with EMR for the endoscopic treatment of rectal carcinoid tumors. A prospective case series with comparison to retrospective controls. Tertiary-care center. From January 2007 to January 2009 we prospectively enrolled consecutive patients with rectal carcinoid tumors less than 16 mm in diameter and with no regional lymph node enlargement shown by CT or EUS. For comparison, we retrospectively randomly selected patients who had undergone EMR for treatment of rectal carcinoid tumors between March 2000 and December 2006. We performed ESD of rectal carcinoid tumors in prospectively enrolled patients. Rate of en bloc resection, rate of histologically complete resection, incidence of complications, and length of procedures. The ESD group contained 31 patients (18 male, 13 female; age range 34-65 years), and the EMR group contained 62 patients (42 male, 20 female; age range 22-77 years). Both groups had similar mean rectal carcinoid tumor diameters (ESD 6.8 +/- 2.4 mm, EMR 7.3 +/- 2.2 mm; P = .106). Resection time was longer in the ESD group than in the EMR group (11.4 +/- 3.7 minutes vs 4.2 +/- 3.2 minutes, P < .001). The en bloc resection rate was 100% (31 of 31) in the ESD group and 95.2% (59 of 62) in the EMR group (P = .213). The histologically complete resection rate was 90.3% (28 of 31) in the ESD group and 71.0% (44 of 62) in the EMR group (P = .035). Suspected perforation occurred in 1 ESD patient (3.2%) and in 1 EMR patient (1.6%), and both patients were successfully managed by conservative measures. Immediate bleeding occurred in 1 ESD patient (3.2%) and in 4 EMR patients (6.5%); all instances of bleeding were controlled endoscopically. Retrospective control study and limited experience at a single center. Compared with EMR, ESD resulted in a higher histologically complete resection rate, had a similar complication rate, and took slightly longer to perform. Given the advantages of complete resection, these findings indicate that ESD may be considered for treatment of rectal carcinoid tumors.