Current Status of Robotic Hepatobiliary and Pancreatic Surgery.

Laparoscopic surgery is performed worldwide and has clear economic and social benefits in terms of patient recovery time. It is used for most gastrointestinal surgical procedures, but laparoscopic surgery for more complex procedures in the esophageal, hepatobiliary, and pancreatic regions remains challenging. Minimally invasive surgery that results in accurate tumor dissection is vital in surgical oncology, and development of surgical systems and instruments plays a key role in assisting surgeons to achieve this. A notable advance in the latter half of the 1990s was the da Vinci Surgical System, which involves master-slave surgical support robots. Featuring high-resolution three-dimensional (3D) imaging with magnification capabilities and forceps with multi-joint function, anti-shake function, and motion scaling, the system compensates for the drawbacks of conventional laparoscopic surgery. It is expected to be particularly useful in the field of hepato-biliary-pancreatic surgery, which requires delicate reconstruction involving complex liver anatomy with diverse vascular and biliary systems and anastomosis of the biliary tract, pancreas, and intestines. The learning curve is said to be short, and it is hoped that robotic surgery will be standardized in the near future. There is also a need for a standardized robotic surgery training system for young surgeons that can later be adapted to a wider range of surgeries. This systematic review describes trends and future prospects for robotic surgery in the hepatobiliary-pancreatic region.

Minimally invasive surgery for esophagogastric junction cancer with Leriche's syndrome-induced ischemic enteritis in the rectum: A case report.

The incidence of esophagogastric junction cancer has been increasing, leading to growing interest in surgical treatment. Leriche syndrome, characterized by occlusion limited to the infrarenal aorta, has not been reported to be associated with ischemic enteritis, and there are no previous reports on the surgical approaches for esophagogastric junction cancer in this disease.We describe the case of a male patient in his fifties with lower abdominal pain and melena who was diagnosed with esophagogastric junction cancer, Leriche syndrome, and ischemic enteritis. Contrast-enhanced computed tomography (CT) showed a hemorrhage from the cancer, occlusion of the abdominal aorta beyond the renal artery branches, and rectal contrast deficiency. Three-dimensional (3D)-CT angiography revealed occlusion from the lumbar artery bifurcation to the distal portions of both common iliac arteries plus numerous collateral pathways, indicating a precarious rectal blood supply. Based on 3D-CT angiography, minimally invasive surgery (MIS) using laparoscopy and thoracoscopy for esophagogastric junction cancer was performed after whole-body control. The patient was discharged without any postoperative complications.Esophagogastric junction cancer with Leriche syndrome can be complicated by ischemic enteritis due to tumor bleeding and fragile collateral pathways. MIS using laparoscopy and thoracoscopy guided by 3D-CT angiography can be safely performed for this disease.

Current Status of Robotic Gastrointestinal Surgery.

Development of surgical support robots began in the 1980s as a navigation and auxiliary device for endoscopic surgery. For remote surgery on the battlefield, a master-slave-type surgical support robot was developed, in which a console surgeon operates the robot at will. The da Vinci surgical system, which currently dominates the global robotic surgery market, received United States Food and Drug Administration and regulatory approval in Japan in 2000 and 2009 respectively. The latest, fourth generation, da Vinci Xi has a good field of view via a three-dimensional monitor, highly operable forceps, a motion scale function, and a tremor-filtered articulated function. Gastroenterological tract robotic surgery is safe and minimally invasive when accessing and operating on the esophagus, stomach, colon, and rectum. The learning curve is said to be short, and robotic surgery will likely be standardized soon. Therefore, robotic surgery training should be systematized for young surgeons so that it can be further standardized and later adapted to a wider range of surgeries. This article reviews current trends and potential developments in robotic surgery.

Prognostic impact of postoperative infection after resection of biliary malignancy: A multicenter retrospective cohort study.

BACKGROUND: The aim of this study was to investigate the prognostic impact of postoperative infections in patients who underwent resection for biliary malignancy, including intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, gallbladder carcinoma, and carcinoma of the ampulla of Vater. METHODS: This study was conducted in an 11-center retrospective cohort study. Patients with biliary tract cancer who underwent curative resection between April 2013 and March 2015 at 11 institutions in Japan were enrolled. We analyzed the prevalence of postoperative infection, infection-related factors, and prognostic factors. RESULTS: Of the total 290 cases, 33 were intrahepatic cholangiocarcinoma, 60 were perihilar cholangiocarcinoma, 120 were distal cholangiocarcinoma, 55 were gallbladder carcinoma, and 22 were carcinoma of the ampulla of Vater. Postoperative infectious complications, including remote infection, were observed in 146 patients (50.3%), and Clavien-Dindo ≥III in 115 patients (39.7%). Postoperative infections occurred more commonly in the patients who received pancreaticoduodenectomy and bile duct resection. Patients with infectious complications had a significantly poorer prognosis than those without (median overall survival 38 months vs 62 months, P = .046). In a diagnosis-specific analysis, although there was no correlation between infectious complications and overall survival in intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, and carcinoma of the ampulla of Vater, infectious complications were a significantly poor prognostic factor in gallbladder carcinoma (P = .031). CONCLUSION: Postoperative infection after surgery for biliary tract cancer commonly occurred, especially in patients who underwent pancreaticoduodenectomy and bile duct resection. Postoperative infection is relatively associated with the prognosis of patients with biliary malignancy, especially gallbladder carcinoma.

C. elegans ATG-5 mutants associated with ataxia.

Intercellular cleaning via autophagy is crucial for maintaining cellular homeostasis, and impaired autophagy has been associated with the accumulation of protein aggregates that can contribute to neurological diseases. Specifically, the loss-of-function mutation in the human autophagy-related gene 5 (ATG5) at E122D has been linked to the pathogenesis of spinocerebellar ataxia in humans. In this study, we generated two homozygous C. elegans strains with mutations (E121D and E121A) at positions corresponding to the human ATG5 ataxia mutation to investigate the effects of ATG5 mutations on autophagy and motility. Our results showed that both mutants exhibited a reduction in autophagy activity and impaired motility, suggesting that the conserved mechanism of autophagy-mediated regulation of motility extends from C. elegans to humans.

High Infiltration of CD163-Positive Macrophages in Intratumor Compartment Predicts Poor Prognosis in Patients With Upper Urinary Tract Urothelial Carcinoma and Radical Nephroureterectomy.

OBJECTIVES: To investigate the prognostic value of CD68- and CD163-positive macrophages in patients with upper urinary tract urothelial carcinoma (UTUC). PATIENTS AND METHODS: This retrospective study enrolled 50 patients (34 men and 16 women) with UTUC who received radical nephroureterectomy (RNU). We evaluated the expression of CD68 and CD163 in the intratumor compartment by immunohistochemistry. The Kaplan-Meier method and Cox proportional hazards regression model were used to evaluate overall survival (OS), cancer-specific survival (CSS), recurrence-free survival (RFS), and bladder recurrence-free survival (BRFS). RESULTS: High infiltration of CD163-positive macrophages in patients with UTUC was significantly correlated with worse OS, CSS, and RFS (P < .05 for all). Multivariate analysis showed that high infiltration of CD163-positive macrophages was an independent negative prognostic factor of OS and CSS in patients with UTUC who received RNU. Lymphovascular invasion was an independent negative prognostic factor of RFS, and high infiltration of CD68-positive macrophages was an independent positive prognostic factor of BRFS. CONCLUSION: This study indicated that high infiltration of CD163-positive macrophages in the intratumor compartment might be a useful prognostic marker for survival in patients with UTUC who receive RNU. Further, high infiltration of CD68-positive macrophages in the intratumoral compartment might be a useful prognostic marker for bladder recurrence in these patients.

Do postoperative infectious complications really affect long-term survival in colorectal cancer surgery? A multicenter retrospective cohort study.

Aim: To investigate the impact of postoperative infection (PI), surgical site infection, and remote infection (RI), on long-term outcomes in patients with colorectal cancer (CRC). Methods: The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 1817 curative stage I/II/III CRC patients from April 2013 to March 2015. Patients were divided into the No-PI group and the PI group. We examined the association between PI and oncological outcomes for cancer-specific survival (CSS) and overall survival (OS) using Cox proportional hazards models and propensity score matching. Results: Two hundred and ninety-nine patients (16.5%) had PIs. The 5-year CSS and OS rates in the No-PI and PI groups were 92.8% and 87.6%, and 87.4% and 83.8%, respectively. Both the Cox proportional hazards models and propensity score matching demonstrated a significantly worse prognosis in the PI group than that in the No-PI group for CSS (hazard ratio: 1.60; 95% confidence interval: 1.10-2.34; P = .015 and P = .031, respectively) but not for OS. RI and the PI severity were not associated with oncological outcomes. The presence of PI abolished the survival benefit of adjuvant chemotherapy. Conclusions: These results suggest that PI after curative CRC surgery is associated with impaired oncological outcomes. This survival disadvantage of PI was primarily derived from surgical site infection, not RI, and PI induced lower efficacy of adjuvant chemotherapy. Strategies to prevent PI and implement appropriate postoperative treatment may improve the quality of care and oncological outcomes in patients undergoing curative CRC surgery.

Feeding gastrostomy and duodenostomy using the round ligament of the liver versus conventional feeding jejunostomy after esophagectomy: a meta-analysis.

Esophageal cancer patients require enteral nutritional support after esophagectomy. Conventional feeding enterostomy to the jejunum (FJ) is occasionally associated with small bowel obstruction because the jejunum is fixed to the abdominal wall. Feeding through an enteral feeding tube inserted through the reconstructed gastric tube (FG) or the duodenum (FD) using the round ligament of the liver have been suggested as alternatives. This meta-analysis aimed to compare short-term outcomes between FG/FD and FJ. Studies published prior to May 2022 that compared FG or FD with FJ in cancer patients who underwent esophagectomy were identified via electronic literature search. Meta-analysis was performed using the Mantel-Haenszel random-effects model to calculate Odds Ratios (ORs) with 95% confidence intervals (CIs). Five studies met inclusion criteria to yield a total of 1687 patients. Compared with the FJ group, the odds of small bowel obstruction (OR 0.09; 95% CI, 0.02-0.33), catheter site infection (OR 0.18; 95% CI, 0.06-0.51) and anastomotic leakage (OR 0.53; 95% CI, 0.32-0.89) were lower for the FG/FD group. Odds of pneumonia, recurrent laryngeal nerve palsy, chylothorax and hospital mortality did not significantly differ between the groups. The length of hospital stay was shorter for the FG/FD group (median difference, -10.83; 95% CI, -18.55 to -3.11). FG and FD using the round ligament of the liver were associated with lower odds of small bowel obstruction, catheter site infection and anastomotic leakage than FJ in esophageal cancer patients who underwent esophagectomy.

Whole-Genome and Plasmid Comparative Analysis of Campylobacter jejuni from Human Patients in Toyama, Japan, from 2015 to 2019.

Campylobacter jejuni is a major causative agent of food poisoning, and increasing antimicrobial resistance is a concern. This study investigated 116 clinical isolates of C. jejuni from Toyama, Japan, which were isolated from 2015 to 2019. Antimicrobial susceptibility testing and whole-genome sequencing were used for phenotypic and genotypic characterization to compare antimicrobial resistance (AMR) profiles and phylogenic linkage. The multilocus sequence typing approach identified 37 sequence types (STs) and 15 clonal complexes (CCs), including 7 novel STs, and the high frequency CCs were CC21 (27.7%), CC48 (10.9%), and CC354 (9.9%). The AMR profiles and related resistant factors were as follows: fluoroquinolones (51.7%), mutation in quinolone resistance-determining region (QRDRs) (GyrA T86I); tetracyclines (27.6%), acquisition of tet(O); ampicillin (7.8%), harboring blaOXA184 or a promoter mutation in blaOXA193; aminoglycosides (1.7%), acquisition of ant(6)-Ia and aph(3')-III; chloramphenicol (0.9%), acquisition of cat. The acquired resistance genes tet(O), ant(6)-Ia, aph(3')-III, and cat were located on pTet family plasmids. Furthermore, three pTet family plasmids formed larger plasmids that incorporated additional genes such as the type IV secretion system. Sequence type 4526 (ST4526; 10.9%), which is reported only in Japan, was the most predominant, suggesting continued prevalence. This study reveals the sequences of the pTet family plasmids harbored by C. jejuni in Japan, which had been unclear, and the acquisition of the insertion sequences in a part of the pTet family plasmids. Because pTet family plasmids can be horizontally transmitted and are a major factor in acquired resistance in Campylobacter, the risk of spreading pTet that has acquired further resistance should be considered. IMPORTANCE Campylobacter jejuni is among the major causes of enteritis and diarrhea in humans in many countries. Drug-resistant Campylobacter is increasing in both developing and developed countries, and in particular, fluoroquinolone-resistant Campylobacter was one of the species included on the priority list of antibiotic-resistant bacteria. Campylobacter drug resistance surveillance is important and has been conducted worldwide. In this study, we performed whole-genome analysis of Campylobacter jejuni isolated from diarrhea patients at a hospital in Toyama, Japan. This revealed the continued prevalence of Campylobacter jejuni ST4526, which has been reported to be prevalent in Japan, and the acquisition of resistance and virulence factors in the pTet family plasmids. The diversity of pTet family plasmids, the major resistance transmission factor, is expected to potentially increase the risk of Campylobacter. The usefulness of whole-genome sequencing in Campylobacter surveillance was also demonstrated.

[A Case of Pathological Complete Response Achieved with Neoadjuvant DCS Therapy in Gastric Cancer].

A 77-year-old man with appetite loss was referred to our hospital. Upper gastrointestinal endoscopy and computed tomography(CT)revealed advanced gastric cancer in the antrum with duodenal and pancreatic invasion. After 6 courses of neoadjuvant docetaxel, cisplatin, and S-1(DCS)therapy, CT revealed marked tumor shrinkage. Distal gastrectomy was performed. Histopathological examination showed no residual tumor cells or lymph node metastasis, and thus, finally, pathological complete response was considered to have been achieved. The patient was doing well and disease-free 3 years later. Thus, neoadjuvant DCS therapy can be a promising treatment option for borderline resectable advanced gastric cancer.

Fat-poor leiomyomatous angiomyolipoma arising from renal parenchyma negative for HMB-45: A case report.

Fat-poor leiomyomatous angiomyolipoma, which is similar to smooth muscle tumors, is positive for smooth muscle markers and melanocytic marker human melanin black 45 (HMB-45). We report a case of fat-poor leiomyomatous angiomyolipoma arising from renal parenchyma negative for HMB-45 diagnosed by combined staining with melanocytic markers HMB-45 and Melan-A.

Prognostic impact of postoperative infection in patients with pancreatic cancer: A multicenter cohort study.

BACKGROUND: Postoperative infection after pancreatectomy in patients with pancreatic cancer often leads to poor prognosis. The aim of this study was to determine the prognostic effect of postoperative infection in patients with pancreatic cancer. METHODS: A multicenter cohort study was performed using a common database of patients with pancreatic cancer who underwent curative pancreatic resections between April 2013 and March 2015 at 15 high-volume centers in Japan. The rate of postoperative infection was determined, and patient demographic characteristics, clinicopathologic factors, and prognostic factors for overall survival were analyzed. RESULTS: Of the 462 eligible patients who underwent curative pancreatectomy, postoperative infection occurred in 141 patients (31%), including 114 surgical site infections (25%), 50 remote infections (11%), and 23 combined infections (5%). Risk factors for postoperative infection included high body mass index, nondiabetes, and longer operation time. In the survival analysis, patients with postoperative infection had significantly worse overall survival than patients without postoperative infection. The median survival times were 21.9 and 33.0 months (P = .023), respectively, for patients with and without postoperative infection. According to the multivariate analysis for overall survival, lack of adjuvant therapy (P = .002), but not postoperative infection (P = .829), predicted poor prognosis. The multivariate analysis revealed that postoperative infection (P < .001) was an independent risk factor for lack of adjuvant therapy. CONCLUSION: Postoperative infection in patients with pancreatic cancer may indirectly worsen the prognosis by preventing timely adjuvant therapy.

Nonbonding/Bonding Molecular Orbital Regulation of Nitrogen-Boron-Oxygen-embedded Blue/Green Multiresonant TADF Emitters with High Efficiency and Color Purity.

Invited for the cover of this issue is the group of H. Sasabe and J. Kido at Yamagata University in Japan. The image depicts the molecular structures of N-B-O embedded multi-resonant thermally activated delayed fluorescent (MR-TADF) emitters, which achieved ultra-pure deep-blue/green emission with high efficiency in OLEDs. Read the full text of the article at 10.1002/chem.202201605.

Influence of transurethral enucleation with bipolar of the prostate on erectile function: Prospective analysis of 51 patients at 12-month follow-up.

BACKGROUND: Transurethral enucleation with bipolar (TUEB) is a safe and effective surgery for benign prostatic obstruction (BPO). However, few data exist concerning the influence of TUEB on erectile function (EF) in patients with BPO. OBJECTIVE: To evaluate the influence of TUEB on EF in patients with BPO at 3- and 12-month follow-up. MATERIAL AND METHODS: We prospectively enrolled 51 patients who underwent TUEB from June 2016 to April 2020. We evaluated maximum urinary flow rate (Qmax), postvoid residual urine (PVR), International Prostate Symptom Score (IPSS), quality of life (QoL), and International Index of Erectile Function-5 (IIEF-5) preoperatively and at 3- and 12-month follow-up. We classified the patients according to their preoperative IIEF-5 score into group 1 (IIEF-5 ≥10; n = 24) and group 2 (IIEF-5 <10; n = 27), and for further evaluation of EF, into subgroups a: severe (IIEF-5 5-7), b: moderate (8-11), c: mild to moderate (12-16), d: mild (17-21), and e: no erectile dysfunction (22-25). Data are displayed as median or median (interquartile range). RESULTS: The study comprised 51 patients with a median age of 75 (70.5-79.5) years. Median prostate and transition zone volumes were 69.5 (46.5-78.8) mL and 30.5 (19-43) mL, respectively. Urinary function improved significantly when comparing respective preoperative, 3-month, and 12-month follow-up values: Qmax (7.6, 12.9, 15.2 mL/s), PVR (50, 0, 0 mL), IPSS (20.5, 9, 6), and QoL (5, 2, 2), respectively. There was no significant change in IIEF-5 score across the three time points: 9, 7, 8. The IIEF-5 score slightly but significantly increased between the preoperative and 12-month follow-up values in group 2 (5, 5, 6) and subgroup a (5, 5, 5). CONCLUSION: TUEB was effective and safe surgery for patients with BPO and showed no significant influence on EF at 12-month follow-up after TUEB in patients with BPO.

Nonbonding/Bonding Molecular Orbital Regulation of Nitrogen-Boron-Oxygen-embedded Blue/Green Multiresonant TADF Emitters with High Efficiency and Color Purity.

In this study, we synthesized and characterized multiresonant thermally activated delayed fluorescent (TADF) materials embedded with nitrogen-boron-oxygen (N-B-O), exhibiting color-tunability between blue and green, namely NBO, m-DiNBO, and p-DiNBO. The three emitter materials showed a high photoluminescence quantum yield (PLQY) and a state-of-the-art narrow full width at half maximum (FWHM) of 96 %/25 nm, 87 %/17 nm, and 99 %/19 nm, respectively. For m-DiNBO and p-DiNBO, the emission color could be tuned from blue to green by regulating the nonbonding/bonding molecular orbital characters. Owing to the expanded planar molecular structure, m-DiNBO and p-DiNBO showed high horizontal dipole ratio (Θ) of 88 % and 92 %, respectively. OLEDs were prepared with NBO, m-DiNBO, and p-DiNBO, exhibiting high external quantum efficiencies of 16.8 %, 24.2 %, and 21.6 %, respectively. NBO and m-DiNBO exhibited pure-blue emission with CIE coordinates of (0.137, 0.142) and (0.126, 0.098), respectively. p-DiNBO showed pure-green emission with a CIE coordinate of (0.258, 0.665).

Protein-losing enteropathy caused by a jejunal ulcer after an internal hernia in Petersen's space: A case report.

BACKGROUND: The incidence of internal hernias has recently increased in concordance with the popularization of laparoscopic surgery. Of particular concern are internal hernias occurring in Petersen's space, a space that is surgically created after treatment for gastric cancer and obesity. These hernias cause devastating sequelae, such as massive intestinal necrosis, fatal Roux limb necrosis, and superior mesenteric vein thrombus. In addition, protein-losing enteropathy (PLE) is a rare syndrome involving gastrointestinal protein loss, although its relationship with internal Petersen's hernias remains unknown. CASE SUMMARY: A 75-year-old man with a history of laparotomy for early gastric cancer developed Petersen's hernia 1 year and 5 mo after surgery. He was successfully treated by reducing the incarcerated small intestine and closure of Petersen's defect without resection of the small intestine. Approximately 3 mo after his surgery for Petersen's hernia, he developed bilateral leg edema and hypoalbuminemia. He was diagnosed with PLE with an alpha-1 antitrypsin clearance of 733 mL/24 h. Double-balloon enteroscopy revealed extensive jejunal ulceration as the etiology, and it facilitated minimum bowel resection. Pathological analysis showed extensive jejunal ulceration and collagen hyperplasia with nonspecific inflammation of all layers without lymphangiectasia, lymphoma, or vascular abnormalities. His postoperative course was unremarkable, and his bilateral leg edema and hypoalbuminemia improved after 1 mo. There was no relapse over the 5-year follow-up period. CONCLUSION: PLE and extensive jejunal ulceration may occur after Petersen's hernia. Double-balloon enteroscopy helps identify and resect these lesions.

Asymmetric Spirobiacridine-based Delayed Fluorescence Emitters for High-performance Organic Light-Emitting Devices.

Invited for the cover of this issue is Hisahiro Sasabe, Junji Kido and co-workers at Yamagata University in Japan. This image depicts that the chemical structure of the acceptor is one of the most important keys to maximize the potential of triazine/acridine-based thermally activated delayed fluorescence (TADF) emitters realizing high external quantum efficiency (EQE) of over 30%. Read the full text of the article at 10.1002/chem.202101188.

Asymmetric Spirobiacridine-based Delayed Fluorescence Emitters for High-performance Organic Light-Emitting Devices.

Recently, researchers have focused on thermally activated delayed fluorescence (TADF) for efficient future lighting and displays. Among TADF emitters, a combination of triazine and acridine is a promising candidate for realizing high-efficiency organic light-emitting devices (OLEDs). However, simultaneous development of perfect horizontal orientation (Θ=100 %) and an external quantum efficiency (EQE) of over 40 % is still challenging. Here, to obtain insights for further improvements of a triazine/acridine combination, various asymmetric spirobiacridine (SBA)-based TADF emitters with a unity photoluminescence quantum yield and high Θ ratio of over 80 % were developed. Furthermore, the substitution effects of the triazine acceptor unit on the photophysical properties were studied, including molecular orientations and OLED performance. The corresponding OLED exhibited sky-blue emission with a high EQE of over 30 %.

Treatment of Gastric Cancer in Japan.

Although the incidence of gastric cancer has decreased because of the lower rate of Helicobacter pylori infection, it still accounts for a large number of deaths in Japan. Gastric cancer is mainly treated by resection, and the rate of radical resection is high in Japan because approximately 50% of cases are diagnosed at an early stage. Treatment advances have increased the number of endoscopic submucosal dissections, and development of laparoscopic surgery and robot-assisted surgery as minimally invasive approaches has yielded results similar to those of conventional surgeries, at least in the short term. Cases for which resection is contraindicated are treated with chemotherapy if performance status can be maintained. Although anticancer drugs are continuously under development, treatment outcomes remain unsatisfactory. As Japan becomes a super-aging society, the number of refractory cases is projected to increase. Therefore, evidence of any benefit for minimally invasive surgery and function-preserving surgery needs to be reported quickly. In this paper, we discuss gastric cancer treatment modalities recommended in the fifth edition of the gastric cancer treatment guidelines and describe recent research findings.

Preoperatively diagnosed gastric collision tumor with mixed adenocarcinoma and gastrointestinal stromal tumor: a case report and literature review.

Reports of gastric collision tumors, comprising adenocarcinoma and gastrointestinal stromal tumor, are extremely rare. Here, we report the case of a 68-year-old male who was diagnosed with a lower-body, moderately differentiated, tubular-type adenocarcinoma and submucosal tumor and underwent an elective D2 distal gastrectomy. The tumor cells of the gastrointestinal stromal tumor were positive for H-caldesmon and CD117, weakly positive for smooth muscle actin and DOG-1, and negative for desmin, S-100 protein, CD31, and AE1/AE3. The tumor had grown into a mixed form of adenocarcinoma and gastrointestinal stromal tumor. Thus, we report the first case of a preoperatively diagnosed collision tumor in the stomach consisting of adenocarcinoma and gastrointestinal stromal tumor.