Results of a Randomized Clinical Study of Gemcitabine Plus Nab-Paclitaxel Versus Gemcitabine Plus S-1 as Neoadjuvant Chemotherapy for Resectable and Borderline Resectable Pancreatic Ductal Adenocarcinoma (RCT, CSGO-HBP-015).

BACKGROUND: The optimal neoadjuvant chemotherapy (NAC) regimen for patients with localized pancreatic ductal adenocarcinoma (PDAC) remains uncertain. This trial aimed to evaluate the efficacy and safety of two neoadjuvant chemotherapy (NAC) regimens, gemcitabine plus nab-paclitaxel (GA) and gemcitabine plus S-1 (GS), in patients with resectable/borderline-resectable (R/BR) PDAC. PATIENTS AND METHODS: Treatment-naïve patients with R/BR-PDAC were enrolled and randomly allocated. They received two cycles (2 months) of each standard protocol, followed by radical surgery for those without tumor progression in general hospitals belonging to our intergroup. The primary endpoint was to determine the superior regimen on the basis of achieving a 10% increase in the rate of patients with progression-free survival (PFS) at 2 years from allocation. RESULTS: A total of 100 patients were enrolled, with 94 patients randomly assigned to the GS arm (N = 46) or GA arm (N = 48). The 2-year PFS rates did not show the stipulated difference [GA, 31% (24-38%)/GS, 26% (18-33%)], but the Kaplan-Myer analysis showed significance (median PFS, GA/GS 14 months/9 months, P = 0.048; HR 0.71). Secondary endpoint comparisons yielded the following results (GA/GS arm, P-value): rates of severe adverse events during NAC, 73%/78%, P = 0.55; completion rates of the stipulated NAC, 92%/83%, P = 0.71; resection rates, 85%/72%, P = 0.10; average tumor marker (CA19-9) reduction rates, -50%/-21%, P = 0.01; average numbers of lymph node metastasis, 1.7/3.2, P = 0.04; and median overall survival times, 42/22 months, P = 0.26. CONCLUSIONS: This study found that GA and GS are viable neoadjuvant treatment regimens in R/BR-PDAC. Although the GA group exhibited a favorable PFS outcome, the primary endpoint was not achieved.

Exploratory prospective, randomized phase II study of neoadjuvant transcatheter arterial chemoembolization plus surgery versus surgery alone for large hepatocellular carcinoma (CSGO-HBP-005): Clinical Study Group of Osaka University, Hepato-Biliary-Pancreatic Group.

AIM: Neoadjuvant transcatheter arterial chemoembolization (TACE) for large tumors is controversial, especially in the minimally invasive surgery era. The aim of this study was to compare features between groups treated with neoadjuvant TACE followed by surgery (TACE + surgery) or upfront surgery for hepatocellular carcinoma >5 cm. METHODS: In this exploratory, multicenter, randomized phase I study, the primary measure was 2-year disease-free survival (DFS). Secondary measures were resection rate, necrosis rate by TACE, 2-year overall survival, and site of recurrence. A total of 30 patients were randomly allocated to each arm. RESULTS: The two arms did not differ in patient characteristics. The median time to surgery from randomization was 48 days for TACE + surgery and 29 for surgery only (p < 0.001). Postoperative morbidities did not differ between arms. The 2-year DFS, overall survival, and resection rates were 56.7%, 80.0%, and 93.3%, respectively, in the TACE + surgery arm, and 56.1%, 89.9%, and 90.0% in the upfront surgery arm. Minimally invasive surgery was carried out in 35.7% in the TACE + surgery arm and in 29.6% in the upfront surgery arm. The median necrosis rate by TACE was 90.0%. In resected specimens, invasion to the hepatic vein was less with TACE + surgery (3.6% vs. 22.2%, p = 0.0380). In cases of 100% necrosis with TACE, 2-year DFS was 100%. Site of recurrence did not differ between groups. CONCLUSION: Neoadjuvant TACE did not improve 2-year DFS, and neoadjuvant TACE allowed delay of surgical treatment without increased morbidity and cancer progress. CLINICAL TRIAL REGISTRATION: UMIN: 000005241.

Influence of Percutaneous Transhepatic Gallbladder Aspiration and Drainage for Severe Acute Cholecystitis on the Surgical Outcomes of Subsequent Laparoscopic Cholecystectomy: Post Hoc Analysis of the CSGO-HBP-017 (CSGO-HBP-017C).

OBJECTIVE: Percutaneous transhepatic gallbladder aspiration (PTGBA) and/or drainage (PTGBD) are useful approaches in the management of acute cholecystitis in patients who cannot tolerate surgery because of poor general condition or severe inflammation. However, reports regarding its effect on the surgical outcomes of subsequent laparoscopic cholecystectomy (LC) are sparse. The aim of this retrospective study was to investigate the influence of PTGBA on surgical outcomes of subsequent LC by comparing the only-PTGBA group, including patients who did not need the additional-PTGBD, versus the additional-PTGBD group, including those who needed the additional-PTGBD after PTGBA. PATIENTS AND METHODS: We conducted a post hoc analysis of our multi-institutional data. This study included 63 patients who underwent LC after PTGBA, and we compared the surgical outcomes between the only-PTGBA group (n = 56) and the additional-PTGBD group (n = 7). RESULTS: No postoperative complications occurred among the 63 patients, and the postoperative hospital stay was 11 ± 12 days. Fourteen patients (22.2%) had a recurrence of cholecystitis, of whom 7 patients (11.1%) needed the additional-PTGBD after PTGBA. Significantly longer operative time (245 ± 74 vs 159 ± 65 min, P = 0.0017) and postoperative hospital stay (22 ± 27 vs 10 ± 9 d, P = 0.0118) and greater intraoperative blood loss (279 ± 385 vs 70 ± 208 mL, P = 0.0283) were observed among patients in the additional-PTGBD group compared with the only-PTGBA group, whereas the rates of postoperative complications (Clavien-Dindo grade ≥3: 0% each) and conversion to open surgery (28.6% vs 8.9%, P = 0.1705) were comparable. CONCLUSION: PTGBA for acute cholecystitis could result in good surgical outcomes of subsequent LC, especially regarding postoperative complications. However, we should keep in mind that the additional-PTGBD after PTGBA failure, which sometimes happened, would be associated with increased operative difficulty and longer recovery.

Clinical Significance of Increased Skeletal Muscle Mass During Nab-Paclitaxel Plus Gemcitabine Treatment in Patients With Advanced Pancreatic Cancer.

OBJECTIVES: The clinical significance of increased skeletal muscle mass during nab-paclitaxel plus gemcitabine (AG) treatment in patients with advanced pancreatic cancer (APC) remains unknown. Therefore, we retrospectively investigated the characteristics of patients after AG treatment to evaluate the clinical significance of increased skeletal muscle mass during treatment. METHODS: From January 2015 to August 2021, 67 patients with APC received AG as first-line chemotherapy at Higashiosaka City Medical Center. Of these patients, 39 received second-line (2L) chemotherapy after AG therapy, and 28 received best supportive care. Patients' characteristics at the end of AG treatment were compared retrospectively between these 2 groups, and the relevant factors at the end of first-line treatment for 2L chemotherapy induction were analyzed. RESULTS: A performance status of 0 to 1 and increased skeletal muscle mass during AG therapy were independently associated with 2L chemotherapy induction in multivariate analysis. A high relative dose intensity (≥50%) in the first 8 weeks of AG treatment was more frequently found in patients with increased skeletal muscle mass during treatment ( P = 0.037). CONCLUSIONS: Increased skeletal muscle mass during AG treatment might contribute to the higher prevalence of 2L chemotherapy induction in patients with APC.

Proximal Resection Line Determination Using Intraoperative Radiography in Laparoscopic Distal Gastrectomy for Gastric Cancer.

BACKGROUND/AIM: Laparoscopic distal gastrectomy for gastric cancer has become a common procedure in many institutions. As manual palpation is impossible, various methods have been developed to identify the location of the tumor and determine the proximal resection line. Intraoperative endoscopy requires manpower and is time-consuming. The authors take an intraoperative X-ray. Here, we demonstrate our methods and outcomes. PATIENTS AND METHODS: We preoperatively applied metal clips just proximal to the tumor through esophagogastroduodenoscopy. During surgery, we applied metal vessel clips to the greater and lesser curvatures of the planned resection line of the stomach and took an intraoperative X-ray to examine the distance between the planned resection line and the tumor. If the distance was appropriate, the stomach was resected on the planned line, and if the distance was judged to be insufficient, the stomach was resected on the more proximal line, as appropriate. An intraoperative frozen section of the proximal resection margin was examined, as appropriate. RESULTS: We performed this method for 71 patients. Tumors were successfully resected together with preoperative endoscopic clips in all patients. In five patients, intraoperative frozen section of the proximal resection margins was positive; however, additional resection confirmed negative margins. One patient underwent total gastrectomy, and the remaining 70 patients underwent distal gastrectomy. CONCLUSION: An intraoperative X-ray seems to be a simple and useful method for identifying the location of the tumor and determining the proximal resection line.

[A Case of Laparoscopic Uterine and Vaginal Resection for Local Recurrence after Abdominoperineal Resection for Anal Canal Cancer].

The patient was an 80s woman. She visited our hospital with chief complaint of melena, and further evaluation revealed anal canal cancer. We performed robot-assisted abdominoperineal resection(D3 lymphadenectomy)and lateral lymph node dissection. The pathological diagnosis was anal canal cancer, muc>por1>tub2, T3N1bM0, pStage Ⅲb. One year after the surgery, she had a mass in the soft tissue of perineum on CT scan and PET-CT showed abnormal accumulation, which was diagnosed as local recurrence. At the same time, she also had a mass with abnormal accumulation in ascending colon, and it was diagnosed as ascending colon cancer. In both cases, we judged radical resection was possible, and the policy of surgery was decided. First, laparoscopic ileocecal resection was performed. The local recurrence lesion became a mass, invading the soft tissue of the perineum, the posterior wall of the vagina, and the cervix. So, we performed laparoscopic excision of local recurrent region together with the uterus and the posterior wall of the vagina. Based on the result of pathological examination, the patient was diagnosed with ascending colon cancer(tub1, pT1bN1aM0, pStage Ⅲa), and recurrence of anal canal cancer. The postoperative course is good and there are no signs of recurrence for 6 months after the operation.

Differences in risk factors for surgical site infection between laparotomy and laparoscopy in gastrointestinal surgery.

Extensive gastrointestinal surgery surveillance data in Japan were analyzed to examine the differences in the risk factors for surgical site infection (SSI) between laparotomy and laparoscopic abdominal procedures. Surgical procedures investigated in the study were gastrectomy, cholecystectomy, colectomy, rectal resection, and appendectomy. A total of 32,629 patients were included in the study. The study participants were divided into two groups according to the year of surgery, 2003-2009 (first study period) and 2010-2015 (second study period), due to the increase in the number of laparoscopic surgeries in the second study period. The incidence of SSI was stratified by three SSI classifications (superficial incisional, deep incisional, and organ/space SSI). Multiple logistic regression analysis was performed to predict the risk factors for SSI. The percentage of laparoscopic surgeries performed has increased linearly since 2010. Patients in the second study period were significantly older and had a higher prevalence of SSI risk factors compared with those in the first study period. In addition, the predictive factors changed substantially in most surgical procedures between the two study periods. Wound class ≥ 3 was a ubiquitous risk factor for superficial incisional SSI (SI-SSI) and organ/space SSI (OS-SSI) in both open (laparotomy) and laparoscopic procedures in the first study period. Meanwhile, in the second study period, operative duration was a ubiquitous risk factor in both procedures. The risk factors for SI-SSI differed from those for OS-SSI in the five abdominal surgeries investigated in the study. Periodic examination of risk factors for SSI is recommended in an aging society.

Do antihypertensive drugs really have antitumor effects? Baseline differences in hypertensive and non-hypertensive patients with advanced pancreatic cancer.

Although the antitumor effects of antihypertensive drugs for patients with advanced pancreatic cancer (APC) have been investigated, their efficacy remains unclear. Previous studies suggest that hypertensive (HT) patients with APC are significantly older than non-HT patients with APC, and that other major baseline differences in patient characteristics which may affect prognosis exist between HT and non-HT patients. It is also possible that antihypertensive drugs lack antitumor activity. Therefore, we herein retrospectively investigated the baseline differences between HT and non-HT patients with APC. From January 2015 to April 2020, 56 patients with APC received nab-paclitaxel plus gemcitabine as first-line chemotherapy at Higashiosaka City Medical Center (Higashiosaka, Japan). Of these 56 patients, 30 were diagnosed with hypertension (HT group); the remaining 26 did not have hypertension (non-HT group). Differences between the two groups were compared and prognostic factors were evaluated. Patients in the HT group had significantly less sarcopenia, a significantly larger body mass index, were significantly older, and significantly more likely to have a regular doctor and primary site in the body and tail of the pancreas than those in the non-HT group. Although no significant difference was found in the treatment response, patients in the HT group were significantly more likely to move to second-line chemotherapy than those in the non-HT group. Survival curves showed that median overall survival (OS) in the HT group was significantly longer (10.5 months) than in the non-HT group (6.8 months, P = .04). Multivariate analysis did not identify the use of antihypertensive drugs as an independent prognostic factor of OS. We identified key baseline differences in the characteristics of APC patients with and without HT, suggesting that major selection bias could occur when investigating the efficacy of antihypertensive drugs in all populations. Therefore, it is possible that antihypertensive drugs lack antitumor activity. To determine the true efficacy of antihypertensive drugs for APC, HT, and non-HT patients in another population should be investigated, or a prospective, randomized, controlled trial conducted that is stratified by HT or non-HT status.

Baseline Factors Predictive of the Receipt of Second-Line Chemotherapy After Nab-Paclitaxel Plus Gemcitabine for Patients With Advanced Pancreatic Cancer.

OBJECTIVE: Second-line (2L) chemotherapy is important for improved survival in patients with advanced pancreatic cancer (APC). However, approximately half of patients with APC do not receive 2L chemotherapy because of disease progression or adverse events. Baseline factors predictive of the receipt of 2L chemotherapy remain unknown. Therefore, we investigated predictive factors for the receipt of 2L chemotherapy in patients with APC. METHODS: Between January 2015 and March 2020, 53 patients with APC received nab-paclitaxel plus gemcitabine (AG) as first-line chemotherapy at our institute. Of these 53 patients, 29 patients received 2L chemotherapy, and 23 patients received best supportive care. Patients' characteristics were compared retrospectively, and predictive factors for the receipt of 2L chemotherapy were evaluated. RESULTS: Sarcopenia and hypoalbuminemia at baseline were independent negative predictive factors for the receipt of 2L chemotherapy in multivariate analysis. Although the presence of sarcopenia did not affect the relative dose intensity through 8 weeks of AG therapy, patients with hypoalbuminemia had a significantly lower relative dose intensity. CONCLUSIONS: Sarcopenia and hypoalbuminemia at baseline might be negative predictive factors for the receipt of 2L chemotherapy after AG treatment in patients with APC.

[A Case of Robotic-Assisted Total Pelvic Exenteration for Locally Advanced Rectal Cancer Invading the Prostate].

The patient was a 60s man, whose chief complaint of melena and weight loss. He visited our hospital, and further evaluation revealed rectal cancer(Rb)invading the prostate with obturator lymph node metastasis. The clinical diagnosis was T4b (prostate)N3M0, Stage Ⅲc. He was administered 4 courses of CAPOX plus bevacizumab. After chemotherapy the primary tumor and lymph nodes showed PR, the diagnosis of ycT4bN1bM0, Stage Ⅲc. We performed robot-assisted total pelvic exenteration. He has been cancer-free for 5 months.

[A Case of Laparoscopic Total Pelvic Exenteration for Sigmoid Colon Cancer Using Infrared Illumination System (IRIS)].

The patient was 80s woman, whose chief complaint of fever and abdominal pain. She visited our hospital, and further evaluation revealed sigmoid colon cancer invading the uterus and abdominal wall. The pooling of pus in the uterus was formed and we diagnosed as pyometra. The clinical diagnosis was T4b(uterus, abdominal wall)N0M0, cStage Ⅱc. We performed laparoscopic sigmoidectomy, uterus and bilateral ovaries. We report a case in which the intraoperative infrared illumination system(IRIS)was used to support the identification of the ureter by near-infrared light and total pelvic exenteration could be safely performed.

Effect of Preserving the Percutaneous Gallbladder Drainage Tube Before Laparoscopic Cholecystectomy on Surgical Outcome: Post Hoc Analysis of the CSGO-HBP-017.

BACKGROUND: When percutaneous transhepatic gallbladder drainage (PTGBD) is followed by laparoscopic cholecystectomy (LC), there is no consensus regarding whether the drainage tube should be preserved or removed before LC. We hypothesized that the surgical results of LC might differ between cases with PTGBD tube preservation versus removal. Here, we investigated how drainage tube preservation or removal affected the surgical outcome of LC. METHODS: Using data from our previous multicenter study, we compared LC outcomes after PTGBD between patients with PTGBD tube preservation versus removal. This study included 208 patients who underwent LC over 12 days after PTGBD. In 83 cases, the PTGBD tube was preserved until LC, and in 125 cases, the tube was removed before LC. The results were verified by propensity score matching with 50 patients in each group. RESULTS: Cases with tube preservation versus removal exhibited significantly longer surgery duration (174 ± 105 min vs 145 ± 61 min, P = .0118) and postoperative hospital stay (14 ± 16 days vs 7 ± 7 days, P < .0001), a significantly higher postoperative complication rate (13.2% vs 3.2%, P = .0061), and a marginally higher incidence of open conversion (12.0% vs 4.8%, P = .0547). Propensity score matching verified the inferior surgical outcomes in cases with tube preservation. CONCLUSIONS: These results imply that when LC is performed > 12 days after PTGBD, the surgical outcome may be inferior when the drainage tube is preserved rather than removed before LC.

Preoperative risk score to predict subtotal cholecystectomy after gallbladder drainage for acute cholecystitis: Secondary analysis of data from a multi-institutional retrospective study (CSGO-HBP-017B).

INTRODUCTION: Subtotal cholecystectomy (STC) has become recognized as a "bailout procedure" to prevent bile duct injury in patients undergoing laparoscopic cholecystectomy (LC). Predictors of conversion to STC have not been identified because LC difficulty varies based on pericholecystic inflammation. We analyzed data from patients enrolled in a previously performed multi-institutional retrospective study of the optimal timing of LC after gallbladder drainage for acute cholecystitis (AC). These patients presumably had a considerable degree of pericholecystic inflammation. METHODS: In total, 347 patients who underwent LC after gallbladder drainage for AC were analyzed to examine preoperative and perioperative factors predicting conversion to STC. RESULTS: Three hundred patients underwent total cholecystectomy (TC) and 47 underwent conversion to STC. Eastern Cooperative Oncology Group Performance Status (ECOG PS) (P < .01), severity of cholecystitis (P = .04), previous history of treatment for common bile duct stones (CBDS) (P < .01), and surgeon experience (P = .03) were significantly associated with conversion to STC. Logistic regression analyses showed that ECOG PS (odds ratio 0.2; P < .0001) and previous history of treatment for CBDS (odds ratio 0.37; P = .0073) were independent predictors of conversion to STC. Our predictive risk score using these two variables suggested that a score ≥2 could discriminate between TC and STC (P < .0001). CONCLUSION: Poor ECOG PS and previous history of treatment for CBDS were significantly associated with conversion to STC after gallbladder drainage for AC.

[A Case of Early Appendiceal Adenocarcinoma Coexisting with High-Grade Appendiceal Mucinous Neoplasm].

We report a case of a female in her fifties with early appendiceal adenocarcinoma coexisting with high-grade appendiceal mucinous neoplasm(HAMN)with a review of the literature. The patient presented to our hospital because of an enlarged appendix noted by contrast-enhanced CT performed for hematuria. Contrast-enhanced CT showed that the appendix had swollen to 10 mm and mucus had accumulated inside, which had no evidence of obvious malignancy. She was followed up on CT once a year. Four years after her first visit, she underwent laparoscopic appendectomy for a definitive diagnosis. There were no adhesions or inflammation in her abdominal cavity, and the appendix root was dissected with an automatic anastomosis device. Her resected specimen macroscopically showed mild wall thickening, but no obvious neoplastic lesion. Pathological examination revealed that in many areas centered on the tip of the appendix, highly columnar atypical epithelium with enhanced mucus production was densely proliferated in the form of glandular tubular and papillary. The nuclei of the proliferating epithelium were large and the fission image was conspicuous, but they remained in the mucosa. Pathological examination diagnosed as HAMN according to the WHO classification. The atypical epithelium in a small area at the tip was particularly strong in nuclear atypia, and showed a strong positive diffusely in p53, which was an image of well-differentiated tubular adenocarcinoma. The pathological diagnosis was V, Type 0-Ⅱb, 2 mm, tub1 in HAMN, pTis, Ly0, V0, Pn0, pPM0, pDM0, pRM0, R0. Six months have passed since the operation, but no recurrence has been observed.

A case report of simple mucinous cyst of pancreas detected by rupture.

INTRODUCTION: Simple mucinous cyst (SMC) of pancreas is a disease defined by the Baltimore Consensus in 2014. Pancreatic mucus-producing neoplasms are considered to be premalignant tumors, but SMC is not considered to have a risk of malignancy or recurrence. PRESENTATION OF CASE: The case was a woman in her 50s with a chief complaint of abdominal pain. A blood exam showed an increase in the inflammatory response, and a slight increase of Amylase. CT showed a cystic lesion 80 mm in size at tail of the pancreas, and disproportionate fat stranding and ascites around it. We diagnosed peritonitis associated with the rupture of a cystic lesion accompanied by pancreatitis. Abdominal pain was improving, and we decided to proceed with the detailed examination. MRI showed a uniform hyper-intensity on T2WI, and a nodular-like hypo-intensity was observed inside, which was enhanced. During the follow-up, the lesion had gradually grown and re-ruptured. As we could not deny malignancy by image findings, distal pancreatectomy was performed. The intracystic fluid was browny and turbid, and Amylase, CEA and CA19-9 of the cystic fluid were elevated. We diagnosed it SMC by histopathological findings. Currently, she had no recurrence for 1 year. DISCUSSION: SMC is a type of true cysts, so rupture was rare. However, if the cyst wall becomes weak due to complications such as acute pancreatitis. It is probable that our case had pancreatitis and the cyst wall was weakened. CONCLUSION: SMC detected by rupture was very rare, so we report this case.

Randomized phase II study of gemcitabine and S-1 combination therapy versus gemcitabine and nanoparticle albumin-bound paclitaxel combination therapy as neoadjuvant chemotherapy for resectable/borderline resectable pancreatic ductal adenocarcinoma (PDAC-GS/GA-rP2, CSGO-HBP-015).

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, and multimodal strategies, such as surgery plus neoadjuvant chemotherapy (NAC)/adjuvant chemotherapy, have been attempted to improve survival in patients with localized PDAC. To date, there is one prospective study providing evidence for the superiority of a neoadjuvant strategy over upfront surgery for localized PDAC. However, which NAC regimen is optimal remains unclear. METHODS: A randomized, exploratory trial is performed to examine the clinical benefits of two chemotherapy regimens, gemcitabine plus S-1 (GS) and gemcitabine plus nab-paclitaxel (GA), as NAC for patients with planned PDAC resection. Patients are enrolled after the diagnosis of resectable or borderline resectable PDAC. They are randomly assigned to either NAC regimen. Adjuvant chemotherapy after curative resection is highly recommended for 6 months in both arms. The primary endpoint is tumor progression-free survival time, and secondary endpoints include the rate of curative resection, the completion rate of protocol therapy, the recurrence type, the overall survival time, and safety. The target sample size is set as at least 100. DISCUSSION: This study is the first randomized phase II study comparing GS combination therapy with GA combination therapy as NAC for localized pancreatic cancer. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000021484 . This trial began in April 2016.

A case of planar-type gastrointestinal stromal tumor of the transverse colon with perforation.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the human gastrointestinal tract. They usually develop in the stomach and small intestine, but extremely rarely in the colon. Although most GISTs form a mass, some cases showing a flatly proliferating lesion called planar-type GIST have been reported in the sigmoid colon and small intestine. Those are often associated with diverticular lesion and/or perforation. We present here a case of planar-type GIST of the transverse colon with perforation. A 49-year-old Japanese woman abruptly complained of abdominal pain, and was clinically diagnosed as perforation of the transverse colon. Partial resection of the transverse colon including the perforated site was done, and no apparent mass lesion was present. Histology showed that spindle cells flatly proliferated around the perforated area and replaced the layers from submucosa to subserosa. Immunohistochemistry revealed that the spindle cells were KIT-, DOG1- and CD34-positive. Codons 557 and 558 of exon 11 of the c-kit gene were heterozygously deleted at the lesional tissue but not at the normal mucosal tissue. Planar-type GIST of the transverse colon has not been reported yet, and the literature search for the similar cases was done.

[A Case of Giant Intestinal GIST That Was Resected Just after TAE].

A 42-year-old woman visited our hospital complaining of fever and diarrhea. She had abdominal swelling and muscular defense. CT revealed a lobulated tumor occupying the lower abdomen. The tumor contained solid and cystic areas. The main artery vascularizing the tumor was the ileocecal artery, so we considered the tumor to be derived from the intestine or mesentery. We anticipated massive bleeding due to resection, and immediately after the embolization of the artery just before the operation. A vascular bundle from the terminal ileum and mesentery was found on the dorsal side of the tumor, and an outflow from the inferior mesenteric vein was also observed. We ligated each vessel and performed ileocecal resection. The operation lasted 4 hours and 18 minutes, with an estimated blood loss of 2,585 mL, requiring the transfusion of 6 units of concentrated red blood cells. According to histopathological findings, tumor cells with spindle-shaped to ellipsoidal nuclei proliferated in bundles and intricately, and immunostaining was positive for c-kit and DOG-1. We identified the tumor as high-risk GIST. The clinical course after the operation was uneventful. She continued to take imatinib for 3 years and is currently alive and without recurrence for 6 years after the operation.