Cecal Tumor Research Articles

Primary malignant neoplasms of the cecal appendix: unusual findings in acute appendicitis

Introduction: To evaluate the prevalence of appendix neoplasia correlating with patient profile, histological types and frequency. Methods: Data collection was performed in the Pathology Department of a General Hospital, with the objective of identifying patients diagnosed with malignant cecal appendix tumors by histopathologic study of specimens from acute appendicitis. Results: The prevalence of malignant primary epithelial neoplasia of the appendix was 1%. Fifty percent of the cases were neuroendocrine tumors, 35% were mucinous, and 15% were adenocarcinomas. The mean age at diagnosis was 41.3 (SD, 20.4) years (range16-81), with a women/men ratio of 3:1. Discussion: Appendiceal neoplasms are rare and should be suspected manly in women over 40 years of age with suggestive symptoms of acute appendicitis. The size, location, extent, margins and presence of mucin are essential findings for the treatment of these patients.

Pimitespib is effective on cecal GIST in a mouse model of familial GISTs with KIT-Asp820Tyr mutation through KIT signaling inhibition

Three families with multiple gastrointestinal stromal tumors (GISTs) caused by a germline Asp820Tyr mutation at exon 17 of the c-kit gene (KIT-Asp820Tyr) have been reported. We previously generated a knock-in mouse model of the family, and the mice with KIT-Asp818Tyr corresponding to human KIT-Asp820Tyr showed a cecal tumor equivalent to human GIST. In the model mice, we reported that tyrosine kinase inhibitor, imatinib, could stabilize but not decrease the cecal tumor volume. In this report, we examined whether a heat shock protein 90 inhibitor, pimitespib (TAS-116), has an inhibitory effect on phosphorylation of KIT-Asp818Tyr and can decrease the cecal tumor volume in the model mice. First, we showed that pimitespib inhibited KIT phosphorylation both dose- and time-dependently in KIT-Asp818Tyr transfected murine Ba/F3 cells. Then, four 1-week courses of pimitespib were orally administered to heterozygous (KIT-Asp818Tyr/+) model mice. Each course consisted of once-daily administration for consecutive 5 days followed by 2 days-off. Cecal tumors were dissected, and tumor volume was histologically analyzed, Ki-67 labeling index was immunohistochemically examined, and apoptotic figures were counted. Compared to the vehicle treated mice, pimitespib administered mice showed statistically significantly smaller cecal tumor volume, lower Ki-67 labeling index, and higher number of apoptotic figures in 10 high power fields (P = 0.0344, P = 0.0019 and P = 0.0269, respectively). Western blotting revealed that activation of KIT signaling molecules was strongly inhibited in the tumor tissues of pimitespib-administered mice compared to control mice. Thus, pimitespib seemed to inhibit in vivo tumor progression effectively in the model mice. These results suggest that the progression of multiple GISTs in patients with germline KIT-Asp820Tyr might be controllable by pimitespib.

S1777 Polyps and an Uninvited Host

Introduction: Blood fluke illness like Schistosomiasis is considered rare in the United States. Most cases are reported in patients that have migrated from endemic zones like Africa or Asia. Occasionally this infection is seen in individuals from non-endemic regions whereby travel history plays an important role in diagnosis. Zoonotic diseases can be life threatening, thus prompt treatment is crucial to avoid major complications. Herein, we present an European individual living in the United States who underwent routine colon cancer screening in which the polyps that were biopsied revealed calcified Schistosoma eggs. Case Description/Methods: A 67-years-old male with past medical history of hypertension, goiter, and hyperlipidemia presented to the outpatient gastroenterology clinic for routine screening. Coloscopy done showed multiple colonic polyps, the largest being 1 cm in diameter. Pathology reported tubular adenomatous polyps with calcified Schistosoma eggs. Patient was asymptomatic and the physical exam was benign. On social and travel history, he pointed out that he lived in Angola from 1971-1973. Treatment with Praziquantel 600 mg three times daily was started, and the patient was asked to be followed up in 3 months. Negative serology was reported after treatment. Colonoscopy done 3 years later showed complete resolution of the polyps. Discussion: Schistosoma is a blood fluke causing Bilharziasis, an infection caused by freshwater parasitic worms. The parasite itself can be found living in certain freshwater snails. About 5 Schistosoma species have been identified to infect the human body with S. Mansoni and S. Japinicum being the main culprit for intestinal disease. Schistosomiasis is more prevalent in Sub-Saharan Africa with approximately 200 million cases reported worldwide. Infection occurs once the cercariae released by the snail penetrates the skin and begins its life cycle. Most individuals are asymptomatic. Migrating eggs cause bowel inflammation by triggering granulomatous reactions resulting in ulcerations, blood loss, and scaring. The same is true for Host immune response. The most common symptoms for intestinal Schistosomiasis are chronic intermittent abdominal pain, poor appetite, and diarrhea. Chronic ulcerations can be seen in severe cases with strictures as late complications. A combination of Polypectomy plus Praziquantel is often use as treatment. Follow up Colonoscopy to assure resolution is recommended.Figure 1.: Endoscopic mucosal removal of a Cecal granular cell tumor.

Endoscopic submucosal dissection of a large cecal tumor extending into the appendiceal orifice in a patient with intact appendix.

Video 1Endoscopic submucosal dissection of a cecal laterally spreading tumor-granular type extending into the appendiceal orifice.

A wolf in sheep’s clothing: concomitant appendicitis with occult cecal adenocarcinoma

We present the case of an 89-years-old female with an atypical presentation of an obstructive acute appendicitis secondary to a cecal carcinoma. The physical exam revealed a distended abdomen with bilateral lower quadrants tenderness without rebound or rigidity. CT scan demonstrated distal small bowel obstruction and ruptured acute appendicitis. Patient was treated conservatively with nasogastric decompression, intravenous fluids, and antibiotics. She later underwent CT guided drainage of a rim-enhancing fluid collection and her symptoms eventually resolved. She returned a week later and a CT imaging showed high grade distal small bowel obstruction, and findings were a 4.5 cm diameter cecal mass. She underwent an exploratory laparotomy and modified right hemicolectomy with ileostomy for. She had an uneventful postoperative course. Pathology revealed poorly differentiated adenocarcinoma of the cecum stage III T4N1Mx. Appendectomy for appendicitis is the most commonly performed emergency operation in the world. Appendicitis are often rare in elderly, with atypical or delayed presentation and expanded differential diagnosis, making preoperative diagnosis challenging. With the increase overall risk of cancer in this age group, occult colonic carcinoma should be high in the differential diagnosis. Three mechanisms potentially leading to obstruction of the appendiceal lumen by the tumor includes: immediate proximity to the lumen, inflammatory changes from the tumor, back pressure on the cecum causing obstruction of the appendix. Despite advances in imaging, local inflammation, collections, and masses may be misleading. The diagnostic accuracy of CT scan reportedly can be as low as 54% for cecal tumors.

A case of cecal granular cell tumor resected by endoscopic submucosal dissection (ESD)

A case of cecal granular cell tumor resected by endoscopic submucosal dissection (ESD)

A case report of Abrikossoff`s tumor of cecum treated by endoscopic submucosal dissection

Introduction. Granular cell tumor (GCT, synonym – Abrikossoff’s tumor) is a benign neoplasm of neuroectodermal differentiation from epithelioid cells originating from Schwann’s cells, with a characteristic sign of the presence of lysosomal granules in the cytoplasm. 5–10% of GCTs are found in the gastrointestinal tract, with the most frequent localization in the esophagus, large intestine (the right colon) and perianal zone. Most often, the tumor occurs at the age of 40–60 years, in women. As a rule, the tumor is single, but it can be multiple and associated with various hereditary syndromes, in particular, type 1 neurofibromatosis. A rare malignant variant of GCT with local spread and the possibility of metastasis has been described. At the moment, less than 100 clinical cases with tumor localization in the cecum have been described.Clinical case. A 36-year-old patient with nonspecific complaints of constipation and recurrent abdominal pain during diagnostic colonoscopy a submucosal formation in the cecum up to 1 cm in diameter, dense, fixed in the submucosa, with an unchanged mucous membrane above it was revealed. A biopsy was taken, in which a granular cell tumor was suspected. The tumor was removed by the endoscopic submucosal dissection, and the subsequent morphological and immunohistochemical studies, which confirmed a granular cell tumor (Abrikossoff’s tumor).Conclusion. Granular cell tumor of the colon is a rare, non-specific tumor that can be detected during routine diagnostic endoscopic examination. The diagnosis of GCT is established by morphological examination and immunophenotyping of the removed neoplasm. Removal of the tumor by the endoscopic submucosal dissection can be a radical method of treatment for patients with GCT in the colon.

An unusual cecal tumor with microsatellite instability

An unusual cecal tumor with microsatellite instability

Two Cases of Endometriosis in the Cecum Detected by Contrast-enhanced Computed Tomography with Air/Carbon Dioxide Insufflation.

We herein report two patients with endometriosis in the cecum. Both patients presented with a protruding, subepithelial tumor on colonoscopy and were diagnosed with cecal endometriosis after surgical resection. It is notable that the cecal lesions were not initially identified on computed tomography (CT), while CT colonography with air/carbon dioxide insufflation resulted in the detection of the cecal tumor. These cases highlight the possibility of false-negative results on conventional CT in patients with cecal endometriosis. We consider CT colonography with air/carbon dioxide insufflation useful for detecting cecal tumors in such cases.

147 EFFECTIVE UNDERWATER ENDOSCOPIC SUBMUCOSAL DISSECTION FOR A SUPERFICIAL CERVICAL ESOPHAGEAL CANCER

Abstract Underwater method is now mainly used in endoscopic mucosal resection of colorectal and duodenal lesions based on the fact that mucosa and submucosa float into the lumen moving away from the muscularis propria after filling with water without submucosal injection. We performed underwater endoscopic submucosal dissection (ESD) for a cervical esophageal lesion. Methods Case report. Results An 81-year-old man with a history of drinking and smoking underwent endoscopy, revealing a 1/3 round superficial cancer in the cervical esophagus. ESD was performed under general anesthesia and tracheal intubation. The lumen was so narrow from natural constriction that a good view could not be secured under CO2 insufflation. Therefore, we tried the underwater method. As the lumen was expanded by filling with 0.9% saline solution, it was possible to secure a visual field. Because the submucosal layer floated up underwater, a circumferential incision and submucosal dissection were completed easily and quickly. Conclusion Endoscopic resection for lesions within a physiologic narrow space is difficult. The underwater method is reported to be useful for treatment of rectal tumors near the dentate line and cecal tumors in the appendiceal orifice. We found that the underwater method made ESD for the cervical esophageal cancer even easier by securing a good view. To our knowledge, this is the first report of underwater ESD for a cervical esophageal cancer.

Comparison of early appendectomy versus conservative management for appendicular lump at Tertiary Care Hospital.

Objectives: The purpose is to compare two options of management of appendicular lump in order to sort out the better one for the benefit and betterment of populace. Study Design: Cross Sectional study. Setting: Peoples Medical College Hospital Nawabshah. Period: 2016 August to August 2018. Material & Methods: Total 50 patients of appendicular lump were included in this research. All patients were divided into 2 groups. Group 1 included those patients undergoing emergency appendectomy. They were admitted, optimized and the required treatment was initiated. Results: Of total 50, 30(60%) were male and 20(40%) were females. Age was between 14 to 51 years. All patients presented with different clinical presentations. Pain in RIF was in 42(84%) patients whereas 47(94%) patients presented with lump in RIF. 20(40%) patients were operated for appendectomy in emergency and 5(10%) patients for right hemi-colectomy. Histopathological diagnosis was inflammation in 24(48%) patients and 1(2%) resulted in cecal tumor. Infected wound was found in 15 (30%) patients, hematoma in 3 (6%), wound dehiscence in 1(2%) and also cecal fistula in 1 (2%). Conclusion: Conservative treatment is better option to treat appendicular lump with least negative results.

Effects of high-fat diet and intestinal aryl hydrocarbon receptor deletion on colon carcinogenesis.

Consumption of a high-fat diet has been associated with an increased risk of developing colorectal cancer (CRC). However, the effects of the interaction between dietary fat content and the aryl hydrocarbon receptor (AhR) on colorectal carcinogenesis remain unclear. Mainly known for its role in xenobiotic metabolism, AhR has been identified as an important regulator for maintaining intestinal epithelial homeostasis. Although previous research using whole body AhR knockout mice has revealed an increased incidence of colon and cecal tumors, the unique role of AhR activity in intestinal epithelial cells (IECs) and modifying effects of fat content in the diet at different stages of sporadic CRC development are yet to be elucidated. In the present study, we have examined the effects of a high-fat diet on IEC-specific AhR knockout mice in a model of sporadic CRC. Although loss of AhR activity in IECs significantly induced the development of premalignant lesions, in a separate experiment, no significant changes in colon mass incidence were observed. Moreover, consumption of a high-fat diet promoted cell proliferation in crypts at the premalignant colon cancer lesion stage and colon mass multiplicity as well as β-catenin expression and nuclear localization in actively proliferating cells in colon masses. Our data demonstrate the modifying effects of high-fat diet and AhR deletion in IECs on tumor initiation and progression.NEW & NOTEWORTHY Through the use of an intestinal-specific aryl hydrocarbon receptor (AhR) knockout mouse model, this study demonstrates that the expression of AhR in intestinal epithelial cells is required to reduce the formation of premalignant colon cancer lesions. Furthermore, consumption of a high-fat diet and the loss of AhR in intestinal epithelial cells influences the development of colorectal cancer at various stages.

Tumor clinicopathological characteristics and their prognostic value in mucinous colorectal carcinoma.

Aim: This study analyzed clinicopathological features of colorectal mucinous carcinoma and their prognostic values. Patients & method: This study enrolled 265 patients with mucinous colorectal cancer. Clinicopathological information and prognosis were reviewed retrospectively. Kaplan-Meier method, log- rank test and COX proportional hazard regression models were used. Results: In postoperative mucinous carcinoma patients (median age 56, 119 [44.9%] female), advanced tumor stage (odds ratio [OR]: 2.378; 95% CI: 1.512-3.741;p=0.0002), poor differentiation (OR: 1.896; CI: 1.217-2.955;p =0.0047) and right-sided tumors (OR: 2.421; CI: 1.145-5.102;p=0.0206) were associated with shorter overall survival. Appendiceal/ileocecal cecal tumors were not different for prognosis. Conclusion: Mucinous colorectal carcinoma exhibits distinct tumor characteristics. Poor differentiation, advanced stage at presentation and the right side serve as negative prognostic factors.

Cecal Tumorigenesis in Aryl Hydrocarbon Receptor–Deficient Mice Depends on Cecum-Specific Mitogen-Activated Protein Kinase Pathway Activation and Inflammation

The aryl hydrocarbon receptor (AhR) is a transcription factor known as a dioxin receptor. Recently, Ahr-/- mice were revealed to develop cecal tumors with inflammation and Wnt/β-catenin pathway activation. However, whether β-catenin degradation is AhR dependent remains unclear. To determine whether other signaling pathways function in Ahr-/- cecal tumorigenesis, we investigated histologic characteristics of the tumors and cytokine/chemokine production in tumors and Ahr-/- peritoneal macrophages. AhR expression was also assessed in human colorectal carcinomas. Of the 28 Ahr-/- mice, 10 developed cecal lesions by 50 weeks of age, an incidence significantly lower than previously reported. Cecal lesions of Ahr-/- mice developed from serrated hyperplasia to adenoma/dysplasia-like neoplasia with enhanced proliferation. Macrophage and neutrophil infiltration into the lesions was also observed early in serrated hyperplasia, although adjacent mucosa was devoid of inflammation. Il1b, Il6, Ccl2, and Cxcl5 were up-regulated at lesion sites, whereas only IL-6 production increased in Ahr-/- peritoneal macrophages after lipopolysaccharide+ATP stimulation. Neither Myc (alias c-myc) up-regulation nor β-catenin nuclear translocation was observed, unlike previously reported. Interestingly, enhanced phosphorylation of extracellular signal-regulated kinase, Src, and epidermal growth factor receptor and Amphiregulin up-regulation at Ahr-/- lesion sites were detected. In human serrated lesions, however, AhR expression in epithelial cells was up-regulated despite morphologic similarity to Ahr-/- cecal lesions. Our results suggest novel mechanisms underlying Ahr-/- cecal tumorigenesis, depending primarily on cecum-specific mitogen-activated protein kinase pathway activation and inflammation.

A case of simultaneous hernia repair and single-incision laparoscopic colectomy for cecum tumor using surgical glove port settled at a fascia defect of the incisional hernia

A case of simultaneous hernia repair and single-incision laparoscopic colectomy for cecum tumor using surgical glove port settled at a fascia defect of the incisional hernia

Crohn\u2019s disease in a developing African mission hospital: a case report

BackgroundA case is reported of innocuous intestinal obstruction requiring surgical intervention that was confirmed to be Crohn’s disease histopathologically in a resource-constrained rural mission hospital in Cameroon.Case presentationA 70-year man of Kumbo origin from Northwest region of Cameroon with a history of crampy right lower-quadrant abdominal pain, non-bloody, non-mucoid diarrhea alternating with constipation presented to my institution. Abdominal examination of the patient revealed an ill-defined mass in the right iliac fossa and visible peristalsis. An abdominal computed tomographic scan and barium enema study confirmed a complex ascending colonic and cecal tumor. The patient underwent exploratory laparotomy. The intraoperative finding was a huge complex inflammatory mass involving the cecum, terminal ileum, and sigmoid colon. He subsequently had sigmoidectomy with end–to-end sigmoidorectal anastomosis and a cecal resection, and the proximal ascending colon was exteriorized because end mucoid fistula and terminal ileostomy were performed. The histopathological diagnosis confirmed Crohn’s disease. The patient subsequently received five courses of adjuvant chemotherapy consisting of azathioprine, methotrexate, mesalamine, and methylprednisolone. He had complete disease remission and subsequently had closure of ileostomy with satisfactory postoperative status. The most recent follow-up abdominal computed tomographic scan and colonoscopy revealed disease-free status. The patient is also currently receiving a maintenance dose of rectal mesalamine and oral omeprazole treatment. He has been followed every 2 months in the surgical outpatient clinic over the last 16 months with satisfactory clinical outcome.ConclusionsCrohn’s disease is uncommon in Africa, and this entity is encountered sparingly. The signs and symptoms of Crohn’s disease overlap with many other abdominal disorders, such as tuberculosis, ulcerative colitis, irritable bowel syndrome, and others. Several publications in the literature describe that it is difficult to make an accurate diagnosis of this disease, despite the fact that many diagnostic armamentaria are available to suggest its presence. Most of the patients with Crohn’s disease are treated conservatively, and a few may require surgical intervention, especially those presenting with complications such as intestinal obstruction, perforations, and abscess as well as fistula formations, as seen in this index patient. Crohn’s disease is considered by many to be a very rare disease in Africa. It is interesting to know that Crohn’s disease, which affects mainly young adults, may debut at any age. The rarity and clinical curiosity of this entity suggested reporting of my patient’s case. Evidence-based up-to-date information on Crohn’s disease is also documented.

Successful Treatment of the Gastrointestinal Manifestation of Prototheca in a Kidney Transplant Recipient: A Case Report

IntroductionThe Prototheca species are achlorophyllic algae and they are recognized pathogens in animals. They have been reported to cause infections in humans; the majority of the infected patients are immunocompromised. Organ transplant recipients are at risk of infection caused by such unusual organisms. The caseHere we present a highly atypical case report of Prototheca mimicking a cecum tumor in a kidney recipient 7 years after the transplantation. Three years before this Prototheca infection, after a native nephrectomy, the patient underwent a complicated duodeno-jejunal reconstruction with feeding catheter jejunostomy. Imaging studies indicated a tumor-like space occupying lesion in the cecum. The patient was treated successfully with colon resection. Detailed histology excluded malignancy and proved Prototheca wickerhamii. DiscussionThe pathogenesis and many biological aspects of human protothecosis are unclear. Usually, treatment involves both medical and surgical approaches. The surgical treatment should be complete excision. The literature suggests an extremely high mortality rate, and therefore we advocate aggressive surgery in organ transplant recipients. This case is the first report of a successfully treated gastrointestinal manifestation of protothecosis in an organ transplant recipient.

Clinical Significance of Lymph Node Metastasis in the Mesentery of the Terminal Ileum in Patients With Right-sided Colon Tumors at Different Locations.

There are limited reports on peri-ileal lymph node metastasis in patients with right-sided colon cancer, and little is known about their clinical significance. This study aimed to examine the role of tumor location in the prevalence and clinical significance of peri-ileal lymph node metastasis in patients with right-sided colon cancer. This is a retrospective study from a prospective cohort database. The study was conducted at a tertiary referral hospital. Patients with right-sided colon cancer treated with radical surgery in a hospital between May 2006 and September 2016 were included. The frequency of peri-ileal lymph node metastasis in the study cohort and the role of tumor location and the clinical characteristics of patients with peri-ileal lymph node metastasis were determined. We examined 752 cases with right-sided colon cancer including 82 cecal, 554 ascending colon, and 116 hepatic flexure cancer. Twenty patients (2.7%) had peri-ileal lymph node metastasis. The incidence of metastasis to peri-ileal lymph nodes was 7.3% (6/82) in patients with cecal cancer, 2.2% (12/554) in patients with ascending colon cancer, and 1.7% (2/116) in patients with hepatic flexure cancer. Three patients had stage III cancer and 17 had stage IV. All 3 patients with positive peri-ileal lymph nodes and stage III cancer had cecal tumors. In contrast, all patients with ascending colon or hepatic flexure cancer and positive peri-ileal lymph nodes had stage IV cancer. The results were limited by the retrospective design of the study and the small number of patients with peri-ileal lymph node metastasis. Peri-ileal lymph node metastasis was rare even in right-sided colon cancer and occurred mainly in stage IV. However, it occurred in some patients with locally advanced cecal cancer. These results suggest that optimal resection of the mesentery of the terminal ileum might have clinical benefit, especially in curative surgery for cecal cancer. See Video Abstract at http://links.lww.com/DCR/A556.

Prevalence and Survival of Cancer After Pancreas-Kidney Transplantation

BackgroundMalignancy is an important cause of mortality in solid organ transplantation. There have been few studies of de novo solid organ malignancy (NSOM) after pancreas-kidney transplantation (PKT). The aim of this study was analyze the prevalence of NSOM and transplant outcomes. MethodsWe studied the development of NSOM after PKT in our center from May 1990 to February 2017. We analyzed demographic characteristics, prevalence of cancer, and survival after cancer diagnosis. We excluded nonmelanoma skin cancer and patients with history of malignancy before transplantation. ResultsWe included 194 patients who received 206 PKTs (184 simultaneous PKTs and 22 pancreas after kidney transplants) with triple immunosuppressive therapy and basiliximab in more than 95%. The mean age at transplantation was 39 ± 7 years and 74% were male patients. Twelve patients developed malignancies (6.1%). Median time from transplant to NSOM was 6.6 (interquartile range [IQR] 0.2–11.7) years. The malignancies were 2 cecal appendix tumors, 2 hematologic tumors, 2 breast tumors, 1 melanoma, 1 native kidney tumor, 1 brain tumor, 1 bladder tumor, 1 prostate tumor, and 1 leiomyosarcoma. Thirty-five of the 194 patients of the whole cohort died throughout the follow-up, 4 of whom died after NSOM diagnosis (11.4%). Patient and grafts survivals were lower in recipients with tumor compared with recipients without tumor, but the difference was not statistically significant: renal graft survival was 80% vs 90% at 10 years (P = .86); and pancreatic graft survival was 45% vs 70% at 10 years (P = .15), respectively. The mean patient survival time from the diagnosis of cancer was 36.6 (IQR 18–54) months. Patient survival after NSOM diagnosis was 90% at 1 year and 50% at 5 years. ConclusionThe prevalence of NSOM in our PKT recipients is low, despite the scarce series of published data for comparison. Also hematologic tumors rate is very low, possibly influenced by age and type of induction.

Short-term outcomes of endoscopic submucosal dissection for superficial cecal tumors: a comparison between extension and nonextension into the appendiceal orifice.

Background:Few studies have investigated the use of endoscopic submucosal dissection (ESD) for cecal tumors extending into the appendiceal orifice. Herein, we assessed the feasibility and safety of ESD for cecal tumors extending into the appendiceal orifice.Methods:We retrospectively examined the outcomes of ESD for 78 patients with 78 cecal tumors (male/female ratio, 40/38; mean [standard deviation, SD] age, 67 [9] years; mean [SD] tumor size, 32 [15] mm), who underwent ESD at the Hiroshima University Hospital between October 2008 and March 2016. The indication for ESD in cecal tumors extending into the appendiceal orifice was recognition of the distal edge of the lesion in the appendix. They were classified into two groups: patients with cecal tumors extending (Group A: 29 patients, 29 tumors) and not extending (Group B: 49 patients, 49 tumors) into the appendiceal orifice. We compared the outcomes of ESD between both groups.Results:No significant differences in clinicopathological characteristics were observed between both groups. The rate of severe submucosal fibrosis in Group A (48%) was significantly higher than that in Group B (24%) (p < 0.05). The mean (SD) procedure speed in Group A (14 [10] mm2/min) was significantly slower than that in Group B (23 [16] mm2/min) (p < 0.01). The en bloc resection rates in Groups A and B were 90% and 96%, respectively. There were no significant differences in adverse events reported between both groups.Conclusions:ESD for cecal tumors with extension into the appendiceal orifice is effective and safe.