Gastrointestinal stromal tumours: consensus statement on diagnosis and treatment

Updates in the Field of Submucosal Endoscopy

Submucosal endoscopy (third-space endoscopy) can be defined as an endoscopic procedure performed in the submucosal space. This procedure is novel and has been utilized for delivery to the submucosal space in a variety of gastrointestinal diseases, such as a tumor, achalasia, gastroparesis, and subepithelial tumors. The main submucosal endoscopy includes peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, and endoscopic submucosal tunnel dissection. Submucosal endoscopy has been used as a viable alternative to surgical techniques because it is minimally invasive in the treatment and diagnosis of gastrointestinal diseases and disorders. However, there is limited evidence to prove this. This article reviews the current applications and evidence regarding submucosal endoscopy while exploring the possible future clinical applications in this field. As our understanding of these procedures improves, the future of submucosal endoscopy could be promising in the fields of diagnostic and therapeutic endoscopy.

Endoscopic resection of GI stromal tumor using full-thickness resection device: tips and tricks

Video 1R0 endoscopic resection of gastric GI stromal tumor using a dedicated gastroduodenal full-thickness resection device.

Histiocytic Sarcoma Secondary to Gastrointestinal Stromal Tumors: A Literature Review

Histiocytic sarcoma (HS) is a rare tumor that may result from the transdifferentiation of preexisting hematolymphoid neoplasms in a subset of patients. There are instances of correlation or concurrence between HS and a number of cancers, particularly B-cell-associated hematopoietic tumors. Only three cases of HS occurring subsequent to or concurrently with gastrointestinal stromal tumors (GIST) have been recorded. Our main objective was to give an overview of demographics, clinical signs and symptoms, histopathological findings, and immunohistochemical and molecular analysis when HS develops secondary to or concurrently with GIST. A search of PubMed, Google Scholar, and ScienceDirect was undertaken using Medical Subject Headings (MeSH) keywords. According to the findings of our review, there were two males (66.6%) and one female (33.3%). The average age of patients at presentation was 59.6 years. On the immunohistochemistry, three patients were positive for cluster of differentiation (CD) 68 (100%), two patients were positive for CD 163 (67%), one patient was positive for leukocyte common antigen (LCA) (33%), and only one patient was positive for CD 4, CD 10, CD 31, CD 45, human leukocyte antigen (HLA)-DR, lysozyme, and vimentin (33%). On molecular investigation, the gastric mass of only one patient (33.33%) contained a KIT mutation on exon 11. Emperipolesis was observed in one patient (33.33%) on histological examination. Our study provides an important overview of the available literature and gives insight into important diagnostic markers of HS when it occurs secondary to or concurrently with GIST.

Comparison of endoscopic full-thickness resection and cap-assisted endoscopic full-thickness resection in the treatment of small (≤1.5 cm) gastric GI stromal tumors

BACKGROUND AND AIMS

With the increasing incidence of small GI stromal tumors (GISTs), endoscopic full-thickness resection (EFTR) and cap-assisted EFTR (EFTR-C) have been suggested as 2 effective resection methods. We aimed to compare the outcomes of EFTR and EFTR-C for the treatment of small (≤1.5 cm) gastric GISTs.

METHODS

This retrospective study included 67 patients who underwent EFTR and 46 patients who underwent EFTR-C at Nanjing Drum Tower Hospital. Clinicopathologic features, adverse events (AEs), and outcomes were compared between the 2 groups. Univariate and multivariate linear and logistic regressions were used to analyze the effects of the procedure on the therapeutic outcomes of patients and adjusted for covariates in the multivariate analysis.

RESULTS

The tumor size in the EFTR group tended to be larger (P = .005). The resection time in the EFTR-C group was shorter than that in the EFTR group (38.3 ± 20.7 minutes vs 15.0 ± 11.8 minutes, P < .001), which retained statistical significance with adjustment for the covariates (adjusted mean difference, 22.2; 95% confidence interval, 15.0-29.4; P < .001). The R0 resection rate of the EFTR group was 94.0% and of the EFTR-C group 97.8% (P = .355). The EFTR-C group was superior to the EFTR group in terms of perioperative therapeutic outcomes, AEs, and postoperative recovery. No recurrence occurred in the EFTR and EFTR-C groups.

CONCLUSIONS

EFTR-C was found to be the preferable technique for small (≤1.5 cm) gastric GISTs with shorter operation times, lower AEs, faster postoperative recovery, and shorter hospitalization times as compared with EFTR.

The Diagnosis of Small Gastrointestinal Subepithelial Lesions by Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy

Endoscopic ultrasonography (EUS) has been widely accepted in the diagnosis of all types of tumors, especially pancreatic tumors, lymph nodes, and subepithelial lesions (SELs). One reason is that the examination can provide a detailed observation, with tissue samples being immediately obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Many SELs are detected incidentally during endoscopic examinations without symptoms. Most SELs are mesenchymal tumors originating from the fourth layer, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas. GISTs are potentially malignant. Surgical treatment is recommended for localized GISTs of ≥20 mm. However, the indications for the diagnosis and follow-up of GISTs of <20 mm in size are controversial. There are several reports on the rapid progression or metastasis of small GISTs. Therefore, it is important to determine whether a SEL is a GIST or not. The main diagnostic method is EUS-FNA. Recently, endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a new biopsy needle has been reported to obtain larger tissue samples. Additionally, various biopsy methods have been reported to have a high diagnostic rate for small GISTs. In local gastric SELs, regardless of the tumor size, EUS can be performed first; then, EUS-FNA/B or various biopsy methods can be used to obtain tissue samples for decision-making in relation to therapy and the follow-up period.

International Society of Paediatric Surgical Oncology (IPSO) Surgical Practice Guidelines

Most children with tumors will require one or more surgical interventions as part of the care and treatment, including making a diagnosis, obtaining adequate venous access, performing a surgical resection for solid tumors (with staging and reconstruction), performing procedures for cancer prevention and its late effects, and managing complications of treatment; all with the goal of improving survival and quality of life. It is important for surgeons to adhere to sound pediatric surgical oncology principles, as they are closely associated with improved local control and survival. Unfortunately, there is a significant disparity in survival rates in low and middle income countries, when compared to those from high income countries. The International Society of Paediatric Surgical Oncology (IPSO) is the leading organization that deals with pediatric surgical oncology worldwide. This organization allows experts in the field from around the globe to gather and address the surgical needs of children with cancer. IPSO has been invited to contribute surgical guidance as part of the World Health Organization Initiative for Childhood Cancer. One of our goals is to provide surgical guidance for different scenarios, including those experienced in High- (HICs) and Low- and Middle-Income Countries (LMICs). With this in mind, the following guidelines have been developed by authors from both HICs and LMICs. These have been further validated by experts with the aim of providing evidence-based information for surgeons who care for children with cancer. We hope that this initiative will benefit children worldwide in the best way possible. Simone Abib, IPSO President Justin T Gerstle, IPSO Education Committee Chair Chan Hon Chui, IPSO Secretary.

Early experience of laparoscopic resection and comparison with open surgery for gastric gastrointestinal stromal tumor: a multicenter retrospective study

The advantages of laparoscopic resection over open surgery in the treatment of gastric gastrointestinal stromal tumor (GIST) are not conclusive. This study aimed to evaluate the postoperative and oncologic outcome of laparoscopic resection for gastric GIST, compared to open surgery. We retrospectively reviewed the prospectively collected database of 1019 patients with gastric GIST after surgical resection at 13 Korean and 2 Japanese institutions. The surgical and oncologic outcomes were compared between laparoscopic and open group, through 1:1 propensity score matching (PSM). The laparoscopic group (N = 318) had a lower rate of overall complications (3.5% vs. 7.9%, P = 0.024) and wound complications (0.6% vs. 3.1%, P = 0.037), shorter hospitalization days (6.68 ± 4.99 vs. 8.79 ± 6.50, P < 0.001) than the open group (N = 318). The superiority of the laparoscopic approach was also demonstrated in patients with tumors larger than 5 cm, and at unfavorable locations. The recurrence-free survival was not different between the two groups, regardless of tumor size, locational favorableness, and risk classifications. Cox regression analysis revealed that tumor size larger than 5 cm, higher mitotic count, R1 resection, and tumor rupture during surgery were independent risk factors for recurrence. Laparoscopic surgery provides lower rates of complications and shorter hospitalizations for patients with gastric GIST than open surgery.

Gastrointestinal stromal tumors diagnosis on multi-center endoscopic ultrasound images using multi-scale image normalization and transfer learning

BACKGROUND

Automated diagnosis of gastrointestinal stromal tumors' (GISTs) cancerization is an effective way to improve the clinical diagnostic accuracy and reduce possible risks of biopsy. Although deep convolutional neural networks (DCNNs) have proven to be very effective in many image classification problems, there is still a lack of studies on endoscopic ultrasound (EUS) images of GISTs. It remains a substantial challenge mainly due to the data distribution bias of multi-center images, the significant inter-class similarity and intra-class variation, and the insufficiency of training data.

OBJECTIVE

The study aims to classify GISTs into higher-risk and lower-risk categories.

METHODS

Firstly, a novel multi-scale image normalization block is designed to perform same-size and same-resolution resizing on the input data in a parallel manner. A dilated mask is used to obtain a more accurate interested region. Then, we construct a multi-way feature extraction and fusion block to extract distinguishable features. A ResNet-50 model built based on transfer learning is utilized as a powerful feature extractor for tumors' textural features. The tumor size features and the patient demographic features are also extracted respectively. Finally, a robust XGBoost classifier is trained on all features.

RESULTS

Experimental results show that our proposed method achieves the AUC score of 0.844, which is superior to the clinical diagnosis performance.

CONCLUSIONS

Therefore, the results have provided a solid baseline to encourage further researches in this field.

Focal segmental glomerulosclerosis and concurrent glomerular microangiopathy after long-term imatinib administration

A 79-year-old Japanese man was admitted to our hospital because of proteinuria and kidney dysfunction. He was diagnosed with chronic myeloid leukemia 13 years before and was treated with imatinib. Deep molecular response was achieved but he developed 1+ proteinuria in the first year, which gradually worsened thereafter. Imatinib was discontinued 12 years later but proteinuria and kidney dysfunction were progressive. Percutaneous kidney biopsy revealed mild mesangial hyper-cellularity and matrix increase, swelling of endothelial cells, and partial double contours of glomerular tufts. Subendothelial edema in the interlobular artery was also noted. Immunofluorescence was not remarkable. Electron microscopy revealed endothelial injury with severe sub-endothelial edema. Since imatinib had already been discontinued, conservative therapy with maximal dose of azilsartan was administered. A second biopsy was performed 1 year later because of further deterioration of kidney function, which revealed markedly increased global glomerulosclerosis and severe interstitial fibrosis and tubular atrophy. Segmental glomerulosclerosis with podocyte hyperplasia was also observed. Electron microscopy revealed glomerulosclerotic changes and partially attenuated endothelial injury. Two and a half years later, proteinuria reduced, progression of kidney dysfunction slowed, and he was independent on dialysis therapy. Molecular response of chronic myeloid leukemia was also maintained. The clinical course suggested that endothelial and podocyte injuries were induced by imatinib, and that the nephrotoxic effects lasted for a few years after discontinuation.

Preoperative imaging of gastric GISTs underestimates pathologic tumor size: A retrospective, single institution analysis

BACKGROUND

How well imaging size agrees with pathologic size of gastric gastrointestinal stromal tumors (GISTs) is unknown. GIST risk stratification is based on pathologic size, location, and mitotic rate. To inform decision making, the size discrepancy between imaging and pathology for gastric GISTs was investigated.

METHODS

Imaging and pathology reports were reviewed for 113 patients. Bland-Altman analyses and intraclass correlation (ICC) assessed agreement of imaging and pathology. Changes in clinical risk category due to size discrepancy were identified.

RESULTS

Computed tomography (CT) (n = 110) and endoscopic ultrasound (EUS) (n = 50) underestimated pathologic size for gastric GISTs by 0.42 cm, 95% confidence interval (CI): (0.11, 0.73), p = 0.008 and 0.54 cm, 95% CI: (0.25, 0.82), p < 0.001, respectively. ICCs were 0.94 and 0.88 for CT and EUS, respectively. For GISTs ≤ 3 cm, size underestimation was 0.24 cm for CT (n = 28), 95% CI: (0.01, 0.47), p = 0.039 and 0.56 cm for EUS (n = 26), 95% CI: (0.27, 0.84), p < 0.0001. ICCs were 0.72 and 0.55 for CT and EUS, respectively. Spearman's correlation was ≥0.84 for all groups. For GISTs ≤ 3 cm, 6/28 (21.4% p = 0.01) on CT and 7/26 (26.9% p = 0.005) on EUS upgraded risk category using pathologic size versus imaging size. No GISTs ≤ 3 cm downgraded risk categories. Size underestimation persisted for GISTs ≤ 2 cm on EUS (0.39 cm, 95% CI: [0.06, 0.72], p = 0.02, post hoc analysis).

CONCLUSION

Imaging, particularly EUS, underestimates gastric GIST size. Caution should be exercised using imaging alone to risk-stratify gastric GISTs, and to decide between surveillance versus surgery.

Gastrointestinal Stromal Tumor as a Rare Cause of Abdominal Mass: A Case Report and Literature Review

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas that can arise from any part of the digestive system. GISTs represent 1% of gastric neoplasms. We report a rare case of a GIST tumor in a 59-year-old woman who presented with abdominal pain and weight loss. Computed tomography (CT) of the abdomen with intravenous contrast revealed a left upper quadrant abdominal mass and biopsy showed GIST. She was treated with imatinib to downsize the tumor prior to undergoing surgical resection of the tumor.

Full-thickness resection device (FTRD) for treatment of upper gastrointestinal tract lesions: the first international experience

Background and study aims  The Full-Thickness Resection Device (FTRD) provides a novel treatment option for lesions not amenable to conventional endoscopic resection techniques. There are limited data on the efficacy and safety of FTRD for resection of upper gastrointestinal tract (GIT) lesions. Patients and methods  This was an international multicenter retrospective study, including patients who had an endoscopic resection of an upper GIT lesion using the FTRD between January 2017 and February 2019. Results  Fifty-six patients from 13 centers were included. The most common lesions were mesenchymal neoplasms (n = 23, 41 %), adenomas (n = 7, 13 %), and hamartomas (n = 6, 11 %). Eighty-four percent of lesions were located in the stomach, and 14 % in the duodenum. The average size of lesions was 14 mm (range 3 to 33 mm). Deployment of the FTRD was technically successful in 93 % of patients (n = 52) leading to complete and partial resection in 43 (77 %) and 9 (16 %) patients, respectively. Overall, the FTRD led to negative histological margins (R0 resection) in 38 (68 %) of patients. A total of 12 (21 %) mild or moderate adverse events (AEs) were reported. Follow-up endoscopy was performed in 31 patients (55 %), on average 88 days after the procedure (IQR 68-138 days). Of these, 30 patients (97 %) did not have any residual or recurrent lesion on endoscopic examination and biopsy, with residual adenoma in one patient (3 %). Conclusions  Our results suggest a high technical success rate and an acceptable histologically complete resection rate, with a low risk of AEs and early recurrence for FTRD resection of upper GIT lesions.

Tyrosine kinase inhibitors significantly improved survival outcomes in patients with metastatic gastrointestinal stromal tumour: a multi-institutional cohort study

Background

The real-world impact of tyrosine kinase inhibitors (tkis) in clinical practice for gastrointestinal stromal tumour (gist) has not been extensively reported. We sought to assess how outcomes have changed over the eras and to evaluate the effect of access to imatinib and sunitinib on survival in patients with unresectable or metastatic gist in British Columbia.

Methods

Patients with metastatic or unresectable gist were allocated to one of three eras: pre-2002, 2002-2007, and post-2007 based on treatment availability (pre-imatinib, post-imatinib, and post-sunitinib). Overall survival (os) and progression-free survival (pfs) were compared between eras. Univariate and multivariate analyses were performed to determine the effects of tumour, patient, and treatment characteristics on survival outcomes.

Results

Of 657 patients diagnosed with gist throughout British Columbia during 1996-2016, 196 had metastatic disease: 23 in the pre-imatinib era, 67 in the post-imatinib era, and 106 in the post-sunitinib era. A significant increase in os, by 53.6 months (p = 0.0007), and pfs, by 29.1 months (p = 0.044), was observed after the introduction of imatinib. The introduction of sunitinib did not significantly affect os or pfs.

Conclusions

Implementation of tkis has drastically improved survival outcomes for patients with metastatic gist by up to 4.55 years in the real-world setting. Our study demonstrates that implementation of tkis in clinical practice has outperformed their benefit predicted in clinical trials.

Resection Combined with TKI Therapy for Resectable Liver Metastases of Gastrointestinal Stromal Tumours: Results from Three National Centres in China

OBJECTIVE

To investigate the differences in the efficacy of hepatic resection combined with tyrosine kinase inhibitor (TKI) therapy versus TKI therapy alone and the timing of the TKI therapy and hepatic resection for resectable liver metastases from gastrointestinal stromal tumours (GISTs).

METHODS

This was a retrospective review of 43 patients confirmed to have resectable liver metastases from GISTs who received TKI treatment alone or the therapy model of hepatic resection combined with TKIs and were admitted to one of 3 institutions between January 2006 and December 2017.

RESULTS

For all liver metastases patients, the 1-, 3- and 5-year survival rates were 97.67%, 88.98% and 66.46%, respectively. The median overall survival (OS) was 85 months. Patients who underwent hepatic resection combined with TKI therapy had a significantly better OS and a trend towards improved progression-free survival (PFS) than patients who received TKIs alone (P = 0.001, mOS 102 months versus 51 months; P = 0.077, mPFS 42 months versus 30 months). Hepatic resection combined with TKI therapy was the only prognostic factor for long-term survival in the multivariate analysis (HR = 0.198, 95% CI 0.048-0.813, P = 0.025). Compared with patients who underwent hepatic resection combined with postoperative TKIs only, patients who underwent hepatic resection combined with perioperative TKIs had a significantly better PFS (P = 0.032, mPFS 29 months versus 19 months) but did not have a significantly better OS (P = 0.662, mOS 92 months versus 102 months). Resection combined with perioperative TKI therapy was the only prognostic factor for PFS in the multivariate analysis (HR = 0.295, 95% CI 0.101-0.862, P = 0.026).

CONCLUSIONS

For patients with resectable liver metastases, hepatic resection combined with TKI therapy was more beneficial in terms of improving prognosis than TKIs alone. In terms of the timing of TKI therapy and hepatic resection, resection combined with perioperative TKIs may prolong PFS more than resection combined with postoperative TKIs only.

Recent Anti-platelet Therapy Revealing Underlying Undiagnosed Gastrointestinal Stromal Tumor in Otherwise Healthy Patient

Gastrointestinal stromal tumors (GIST) are uncommon tumors of the gastrointestinal (GI) tract that arise from primitive mesenchymal cells. Usually, GIST presents as chronic gastrointestinal symptoms or obscure gastrointestinal bleed. Not many cases have been reported in the literature with acute symptoms in the setting of recent aspirin use. We report a case of 70-year-old male otherwise healthy who presented to the hospital with the complaint of black tarry stool for the past two days after taking one tablet of aspirin once a day for two days. The patient underwent upper endoscopy which showed a moderate size polypoid mass in the gastric fundus. Initially, standard endoscopic biopsy was negative for malignancy, due to high suspicion for GIST, later the patient underwent upper endoscopic ultrasound with fine-needle aspiration which confirmed low-grade GIST.

GIST identified during bariatric surgery: to treat or not to treat?

BACKGROUND

Gastrointestinal stromal tumors (GIST) are rare GI tumors that compose 1% of GI tumors. With the rise in obesity, bariatric surgery is becoming an increasingly common procedure and the incidental GISTs in this population have been noted more often than in the general population.

OBJECTIVE

We evaluated and characterized the incidental GISTs in our bariatric surgical population.

SETTING

The study was completed at a Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program-accredited academic hospital system.

METHODS

All GISTs identified during Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy between January 1, 2005 and December 31, 2016 were evaluated. Typical demographic, clinicopathologic, treatment, follow-up, and outcome data were recorded.

RESULTS

Within the 2655 bariatric surgeries at our institution, 17 GISTs were identified (.64%). Mean age was 54 years; 94% of lesions were identified intraoperatively. Lesions were identified in the fundus (29.4%) or body (70.6%), were unifocal, and <1 cm; 94.1% of resections had clear margins. Histology revealed 88.2% spindle cell and 11.8% mixed histology with <5 mitoses/50 fields, portending a low malignancy potential. Follow-up included the bariatric surgeon and oncology consult; 17.6% were recommended by oncology for computed tomography surveillance. No recurrences were recorded.

CONCLUSION

We present the largest cohort to date of incidental GISTs in a bariatric population. A diligent intraoperative examination of the serosa in the left-behind portion of the remnant in bypass and the discarded remnant in sleeves allows the bariatric surgeon the opportunity to leave the patient cancer-free after removal of incidental tumor.

Multiband mucosectomy versus endoscopic submucosal dissection and endoscopic submucosal excavation for GI submucosal tumors: short and long term follow-up

AIMS

To evaluate the short- and long-term outcomes of 3 different endoscopic dissection techniques for upper gastrointestinal (GI) submucosal tumours (SMTs).

METHODS

Data for 135 patients withGI SMTs who underwent multiband mucosectomy (MBM), endoscopic submucosal dissection (ESD), or endoscopic submucosal excavation (ESE) were retrospectively assessed. The en bloc resection rate, endoscopic complete resection rate, operation time, potential complications and local recurrence rate were compared.

RESULTS

No significant differences were observed in the rate of endoscopic complete resections and pathologic complete resections among the three groups. For SMTs > 15 mm in width, the lowest en bloc resection rate was found for MBM (P = 0.000). MBM was also associated with the shortest procedure time, lowest perforation rate and lowest rate of major bleeding. ESE was the most effective procedure for muscularis propria (MP) lesions but was associated with the longest operation time (P < 0.01). The ESD and ESE groups had similar perforation rates (P > 0.05). No differences were observed in 4-year local recurrence rates among the groups (P = 0.945).

CONCLUSIONS

MBM is a simple and effective method for the treatment of small SMTs and achieves clinical success rates similar to those of ESD and ESE. However, ESD and ESE are preferable for larger and deep lesions and are associated with a longer operation time. Nonetheless, all 3 techniques resulted in a low 4-year local recurrence rate. Large-scale randomized clinical trials are needed to further investigate these results.

Radiofrequency ablation versus resection for resectable liver metastases of gastrointestinal stromal tumours: Results from three national centres in China

OBJECTIVE

The aim of the present study was to compare outcomes after curative intent radiofrequency ablation and resection in patients with resectable liver metastases of Gastrointestinal Stromal Tumours (GISTs) after pre-operative tyrosine kinase inhibitor (TKI) treatment.

METHODS

We retrospectively analysed data from 25 patients diagnosed with resectable liver metastases from GISTs who received pre-operative TKI treatment, who received radiofrequency ablation or resection and post-operative TKI treatment, and who were admitted to 3 institutions from January 2009 to December 2017.

RESULTS

Ten patients (10/25, 40.00%) underwent RFA combined with post-operative TKI treatment, and 15 (15/25, 60.00%) patients were treated with hepatic resection combined with post-operative TKI treatment. There were fewer post-operative complications (10.00% vs. 53.33%, P = 0.04) and shorter length of stay (4 vs. 9 days, P = 0.00) in the RFA group. After a median follow-up of 26 months, the 1-, 3-, and 5-year survival rates were 100.00%, 75.00%, 55.00%, respectively. The RFA group had a lower median PFS (P = 0.007, mPFS: 9 months versus 29 months), but overall survival was not influenced by the treatment modality compared with the resection group (P = 0.413, mOS: 47 months versus not reached).Hepatic resection combined with post-operative TKI treatment was the only prognostic factor for PFS in univariate analysis (HR = 0.071, 95% CI: 0.007-0.759, P = 0.029).

CONCLUSIONS

For patients with resectable liver metastases from GISTs after receiving pre-operative TKI treatment, compared with resection, ablation seemed to be associated with shorter progression-free survival, but RFA offered comparable overall survival, and the post- procedure morbidity and lengths of stay were significantly lower. With complete ablation of the targeted tumours, our results suggest that RFA is an acceptable option in selected patients.

Computer-aided diagnosis of gastrointestinal stromal tumors: a radiomics method on endoscopic ultrasound image

PURPOSE

The purpose of our study is to propose a preoperative computer-aided diagnosis system based on a radiomics method to differentiate gastrointestinal stromal tumors (GISTs) of the higher-risk group (HRG) from those of the lower-risk group (LRG) on endoscopic ultrasound (EUS) images.

MATERIALS AND METHOD

Gastro-EUS (G-EUS) images of four different risk level GISTs were collected from 19 hospitals. The datasheet included 168 case HRG GISTs and 747 case LRG GISTs. A radiomics method with image segmentation, feature extraction, feature selection and classification was developed. Here 439 radiomics features were firstly extracted, and then, the least absolute shrinkage selection operator (lasso) model with a tenfold cross-validation and 31 bootstraps was used to reduce the dimension of feature sets. Finally, random forest was applied to establish the classification model.

RESULTS

The proposed model differentiated 32 case HRG GISTs from 149 case LRG GISTs. Result for the testing set achieved the area under the receiver operating characteristic curve of 0.839, the accuracy of 0.823, the sensitivity of 0.813 and the specificity of 0.826.

CONCLUSION

The model could increase preoperative diagnostic accuracy and provide a valuable reference for the doctors.

Treatment recommendations for small gastric gastrointestinal stromal tumors: positive endoscopic resection

Objectives: To evaluate the safety and efficacy of endoscopic resection and discuss the treatment strategy of small gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. Material and methods: The data of 713 patients, who underwent endoscopic submucosal dissection (ESD) for gastric submucosal tumors (SMTs), were retrospectively analyzed. We investigated the clinicopathological features and analyzed the risk potential of small gastric GISTs, and documented therapeutic and follow-up outcomes. We also compared the follow-up results between operated patients and 58 patients who were suspected of small gastric GISTs and underwent regular surveillance under endoscopic ultrasound (EUS) in the same period. Results: GISTs were the most common gastric SMTs (289 cases, 40.5%), of which small GISTs were found in 250 cases. The mitotic index was less than 5 in all cases. However, 122 out of 250 cases (48.8%) had adverse factors under EUS, which were related to tumor size (p < .01). ESD was successfully performed in all patients, and no serious complication or perioperative death occurred. The follow-up period for 42.07 ± 22.49 months revealed improvement of symptoms in 80.2% patients and showed no recurrence or metastasis. Of the 58 patients selected for EUS surveillance, 48 (82.8%) presented with gastrointestinal symptoms and 41 out of 48 (85.4%) were not relieved during follow-up and 16 (27.6%) with severe psychological problems. Conclusions: ESD is a safe and effective treatment for small GISTs, which helps to confirm the diagnosis, improve symptoms and reduce the psychological pressure. Thus, we recommend endoscopic resection is a good option for small gastric GISTs once diagnosed.

Endoscopic Enucleation Is Effective and Relatively Safe in Small Gastric Subepithelial Tumors Originating from Muscularis Propria

BACKGROUND

Gastric subepithelial tumors originating from muscularis propria (MP) are usually benign, but some have malignant potential.

AIMS

The aim of this study was to evaluate the utility of endoscopic enucleation for the diagnosis and treatment of MP tumors.

PATIENTS AND METHODS

From January 2010 to February 2018, eighty patients with gastric MP tumors underwent endoscopic enucleation at our hospital. Band ligation and resection (BLR) or endoscopic muscularis resection (EMD) was performed based on considerations of tumor size (≤ 12 mm or > 12 mm). Tumor characteristics, procedure times, complete resection rates, adverse events and recurrence were analyzed.

RESULTS

Eighty patients with 82 lesions were eligible for inclusion in this study. BLR was used to treat 41 lesions. For these lesions, mean tumor size was 9.5 mm, median procedural time was 17.6 min (range 4-52), and the endoscopic complete resection rate was 100% (41/41). Perforation was developed in four patients, and was closed by endoscopic clipping. EMD was used to treat 41 lesions. Median procedure time was 66.1 min (range 12-260) and the endoscopic complete resection rate was 85.4% (35/41). Perforation occurred in eight patients, four patients received endoscopic treatment and four underwent surgery. Tumor recurrence was not observed in any patient over follow-up (mean 26.3 months).

CONCLUSION

Endoscopic enucleation appears to offer an effective, relatively safe means for diagnosing and treating gastric subepithelial tumors originating from the MP, and BLR provides a straightforward, effective, and relatively safe treatment for small MP tumors (≤ 12 mm).

Clinicopathologic features and outcomes of gastrointestinal stromal tumors arising from the esophagus and gastroesophageal junction

Background

Our aim was to characterize the clinicopathological features and outcomes of gastrointestinal stromal tumors (GISTs) arising from the esophagus and gastroesophageal junction (GEJ) and describe the survival of patients treated at our institution as well as from a national hospital-based registry.

Methods

Twenty-eight cases were identified using the Mayo Clinic Cancer Registry from 1997 to 2016, and 1,010 cases from the National Cancer Database (NCDB) between 2004 and 2014, with analysis of TNM staging, histopathological features, mitotic index, immunohistochemical studies, and KIT mutational analysis.

Results

At Mayo Clinic, the tumors ranged in size from 0.3-13 cm (mean 5.40 cm). IHC results were: CD117 (KIT) in 100% (23/23 cases) and DOG1 in 100% (6/6), followed by CD34 (85.7%, 12/14), smooth muscle actin (27.8%, 5/18), desmin (18.2%, 2/11), and S-100 protein (13.3%, 2/15). Mutational analysis (performed in 10 cases) showed KIT exon 11 mutations in 8 cases; KIT mutation was not identified in 2 cases (presumed wild-type). Two-thirds of patients underwent surgery, of which 70% had an esophagectomy. Fourteen patients received adjuvant imatinib mesylate. Five patients had liver metastases at the time of diagnosis; none had lymph node metastases. A total of 38.9% of cases had recurrent or metastatic disease. Complete clinical follow-up was available for 10 patients (median follow-up duration 31.5 months; range, 10-145 months): one (male) had a local recurrence at the anastomotic site and one (female) suffered a liver metastasis; the others were either disease-free or had stable disease at the time of last follow-up. There was a significant association seen among metastatic disease and mitotic count >5/50 high-powered field (HPF) (P=0.016), with median mitotic rate 90/50 HPF (range, 7-500) for metastatic tumors versus 6/50 HPF (range, 0-100) for non-metastatic tumors. For metastatic disease, median tumor size was 7.3 cm (range, 1-66 cm) compared to 4.8 cm (range, 0.02-71 cm) for non-metastatic disease, which was also statistically significant (P≤0.0001). Two hundred and fifty-eight NCDB cases were risk stratified using the Joensuu criteria. Among 89 low risk category tumors, only 2 (2.2%) were ultimately metastatic. A total of 10.9% (15/138) of high risk category tumors were metastatic. The median overall survival (OS) from the time of diagnosis for the Mayo Clinic cohort was 129.5 months (95% CI, 55.7-not reached), with 5-year OS 85.7%. Median OS for the NCDB cohort was 135.95 months (95% CI, 104.08-not reached) with 5-year OS 68.2%. Superior OS was seen in females (HR 0.67, 95% CI, 0.49-0.89, P=0.006).

Conclusions

Among esophageal and GEJ GISTs, metastatic disease was associated with increased mitotic count and increased tumor size. Men were found to have inferior OS. The Joensuu risk criteria were validated for risk stratification of esophageal and GEJ GISTs.

Current Standard and Future Perspectives in the Treatment of Gastrointestinal Stromal Tumors

The origin of gastrointestinal stromal tumors (GIST) from interstitial cells of Cajal or their precursor cells has been understood since the early 1990s. The first mutations within the KIT-gene have been described in the late 1990s. Even though these mutations were the breakthrough of small molecular therapy, we still do not know the factors responsible for their malignant transformation. Until then, we can only speak of recurrence risk. This review gives an introduction on the current understanding of GIST and highlights the remaining questions for diagnosis, tumor progression, and treatment in progressive disease.

Comparison of submucosal tunneling biopsy versus EUS-guided FNA for gastric subepithelial lesions: a prospective study with crossover design

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound-guided fine needle aspiration (FNA) for gastrointestinal subepithelial lesions (SELs) has limited diagnostic accuracy due to technical problems and small lesion size. We previously reported a novel submucosal tunneling biopsy (STB) technique for sampling SELs. This study aimed to evaluate the diagnostic ability and safety of STB compared to that of FNA for SELs.

PATIENTS AND METHODS

The study was a non-randomized, prospective comparative study with crossover design in patients with endoluminal gastric SELs. Forty-three patients, including 29 cases with lesions < 2 cm were enrolled. A crossover design with 2 intervention stages (Group A: FNA followed by STB for 23 SELs, Group B: STB followed by FNA for 20 SELs) was implemented. The primary outcome was the diagnostic yield (DY). Secondary outcomes were technical success rate, procedure time, complication rate, and sample quality.

RESULTS

The DY of STB was significantly higher than that of FNA (100 % vs. 34.8 %; P  < 0.0001) in group A, including 100 % in overall STB. The technical success rate of STB was significantly higher than that of FNA (100 % vs. 56.5 %; P  = 0.0006), whereas the median procedure time of STB was significantly longer than that of FNA (37 minutes vs. 18 minutes; P  < 0.0001). The median specimen area of STB samples was markedly larger than that of FNA samples (5.54 mm 2 vs. 0.69 mm 2 ; P  < 0.001). No complications occurred in either method.

CONCLUSIONS

 STB had significantly superior diagnostic ability and a more adequate sample quality than FNA for endoluminal gastric SELs, indicating the suitability of STB for small SELs.

CLINICAL TRIAL REGISTRATION

UMIN 000006754.

Elective Surgery of Umbilical Hernia as a First Clinical Manifestation of a Gastrointestinal Stromal Tumor (Gist) - Case Report

Gastrointestinal stromal tumor is a rare pathology. GISTs account for 0.3-1% of all tumors of the gastrointestinal tract. At the same time, this type of cancer is the most common, malignant, non-epithelial tumor of the gastrointestinal tube. Over 90% of GISTs are found in the stomach and small intestine. This cancer usually develops without characteristic clinical symptoms and is diagnosed incidentally. This clinical situation, in which the first symptom of a GIST-pattern tumor includes a fully-symptomatic, non-complicated umbilical hernia, is an unprecedented anomaly. This work presents a case report of a 77-year old female patient undergoing elective surgery, in which the contents of the hernial sac included a stromal tumor. Disseminated, multi-focal progression of the disease was found intraoperatively. Postoperative histopathology and immunohistochemistry revealed a gastrointestinal stromal tumor GIST of the spindle cell type, showing a CD-117, CD-34, SMA expression with possible starting point in the small intestine.

LAPAROSCOPIC RESECTION OF GASTROINTESTINAL STROMAL TUMORS (GIST)

BACKGROUND

Gastrointestinal mesenchymal or stromal tumors (GIST) are lesions originated on digestive tract walls, which are treated by surgical resection. Several laparoscopic techniques, from gastrectomies to segmental resections, have been used successfully.

AIM

Describe a single center experience on laparoscopic GIST resection.

METHOD

Charts of 15 operated patients were retrospectively reviewed. Thirteen had gastric lesions, of which ten were sub epithelial, ranging from 2-8 cm; and three were pure exofitic growing lesions. The remaining two patients had small bowel lesions. Surgical laparoscopic treatment consisted of two distal gastrectomies, 11 wedge gastric resections and two segmental enterectomies. Mechanical suture was used in the majority of patients except on six, which underwent resection and closure using manual absorbable sutures. There were no conversions to open technique.

RESULTS

Mean operative time was 1h 29 min±92 (40-420 min). Average lenght of hospital stay was three days (2-6 days). There were no leaks, postoperative bleeding or need for reintervention. Mean postoperative follow-up was 38±17 months (6-60 months). Three patients underwent adjuvant Imatinib treatment, one for recurrence five months postoperatively and two for tumors with moderate risk for recurrence .

CONCLUSION

Laparoscopic GIST resection, not only for small lesions but also for tumors above 5 cm, is safe and acceptable technique.

MDCT imaging of the stomach: advances and applications

The stomach may be involved by a myriad of pathologies ranging from benign aetiologies like inflammation to malignant aetiologies like carcinoma or lymphoma. Multidetector CT (MDCT) of the stomach is the first-line imaging for patients with suspected gastric pathologies. Conventionally, CT imaging had the advantage of simultaneous detection of the mural and extramural disease extent, but advances in MDCT have allowed mucosal assessment by virtual endoscopy (VE). Also, better three-dimensional (3D) post-processing techniques have enabled more robust and accurate pre-operative planning in patients undergoing gastrectomy and even predict the response to surgery for patients undergoing laparoscopic sleeve gastrectomy for weight loss. The ability of CT to obtain stomach volume (for bariatric surgery patients) and 3D VE images depends on various patient and protocol factors that are important for a radiologist to understand. We review the appropriate CT imaging protocol in the patients with suspected gastric pathologies and highlight the imaging pearls of various gastric pathologies on CT and VE.

How to approach Incidentally detected Gastrointestinal Stromal Tumor during Laparoscopic Sleeve Gastrectomy: A Report of Two Cases

Laparoscopic sleeve gastrectomy (LSG) is a frequently used bariatric surgery method. It is possible to incidentally detect gastrointestinal stromal tumors (GISTs) of stomach or other gastric tumors during this procedure. In the literature, there is limited data about cooccurrence of GIST in obesity, and treatment of such cases is still controversial. On the contrary, currently accepted treatment of local and nonmetastatic GIST cases is surgery alone, and of cases with systemic disease is surgery combined with imatinib mesylate therapy. Incidental detection of GIST during bariatric surgery may require a modification in the planned procedure, and an extensive exploration and picking a convenient surgical procedure will become necessary. Here, we present two cases – a gastric GIST and a GIST of small intestine – both of which were incidentally detected during LSG performed for obesity.

Effectiveness of Endoscopic Ultrasonography during Double Balloon Enteroscopy for characterization and management of small bowel submucosal tumours

BACKGROUND

Characterization of small bowel submucosal tumours is challenging, requiring additional investigations. Endoscopic Ultrasonography performed during Double Balloon Enteroscopy, appeared a promising technique although it has not been fully evaluated. The aim was to determine the effectiveness of this technique for characterization and management of sub mucosal tumours in a large cohort of patients.

METHODS

Patients with suspected small bowel tumours, who underwent Endoscopic Ultrasonography performed during Double Balloon Enteroscopy in our Institution between 2005 and 2013, were reviewed. Demographic data, clinical, endoscopic and radiological findings, therapeutic management, final diagnosis and follow-up were analyzed.

RESULTS

30 patients (19 male; median age 61.5) affected by submucosal tumours were included in the study. Endoscopic Ultrasonography performed during Double Balloon Enteroscopy was successfully performed in all cases providing a correct characterization of 19 submucosal tumours (63%). Based on the ultrasonographic characteristics 8 patients were treated endoscopically, 16 were referred to surgery, and 6 were managed conservatively.

CONCLUSION

Our results suggest that Endoscopic Ultrasonography performed during Double Balloon Enteroscopy is a safe and useful technique for submucosal tumours characterization. This procedure may be applied in clinical practice when small bowel tumours are encountered, to confirm the diagnosis and provide the most appropriate management.

Pediatric/"Wildtype" gastrointestinal stromal tumors

Pediatric/"Wildtype" gastrointestinal stromal tumor (P/WT-GIST) is a rare cancer, distinct and markedly different from the phenotype found predominantly in older patients (adult, non-wildtype GIST). Having a different molecular signature, it is not responsive to standard adjuvant therapies utilized in adult GIST, and surgery remains the only effective cure. However, even with presumed complete resections in patients with localized disease at presentation, recurrence rates are high. Furthermore, it is an indolent cancer that can persist for decades, and treatment strategies must balance the possible morbid risks of intervention with the reality of preserving quality of life in the interim. Effective adjuvant therapies remain elusive, and research is critically needed to identify both targets and drugs for treatment consideration.

Malignant Retroperitoneal Extra-Gastrointestinal Stromal Tumor: A Unique Entity

Extra-gastrointestinal stromal tumors (EGISTs) are a recently described group of tumors. A handful of less than 70 cases have been reported in English literature, so far, to the best of our knowledge. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the alimentary canal. EGISTs are a unique entity, which require distinction from GISTs because, even though, they exhibit similar histology and immunohistochemistry to GISTs, they occur outside the gastrointestinal tract, i.e. in omentum, mesentery, retroperitoneum, etc. and have different behavior patterns as far as their prognosis and management are concerned. Retroperitoneal sub-group of EGISTs is extremely rare and we report such a case of primary malignant EGIST of the retroperitoneum which presented as a soft tissue mass on radiological evaluation. The tumor turned out to be a histopathological surprise, and could be distinctively labeled as EGIST only after morphological and immunohistochemical studies. It is imperative for radiologists, pathologists and oncologists, among other clinicians, to be able to recognize and understand the presentation of this group of tumors due to their rapid progression and poor prognosis, so that an early diagnosis and management may be able to improve the final disease outcome.

Incidental finding of GIST during obesity surgery

BACKGROUND

The purpose of this study was to review the incidence of incidental gastrointestinal stromal tumors (GISTs) in a cohort of morbidly obese patients undergoing laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB), analyzing surgery indication, morbidity, and follow-up data.

METHODS

All cases with incidental GISTs found were reviewed.

RESULTS

Two thousand six hundred three patients underwent obesity surgery founding a gastric GIST in eight patients (incidence 0.31 %). Mean tumor size was 7.65 mm (range 2.5-13 mm) with the majority of the lesions located in the fundus of the stomach. All lesions had negative resection margins. At a mean follow-up of 30 months, all patients were disease-free.

CONCLUSION

The long-term disease-free survival of 100 % in our study establishes laparoscopic wedge resection during RYGB and LSG as safe and effective in treating incidental gastric GISTs <2 cm.

Ligation-assisted endoscopic enucleation for the treatment of colorectal submucosal tumours originating in the muscularis propria

AIM

A ligation-assisted endoscopic enucleation (EE-L) technique was developed and was evaluated to determine its efficacy and safety for treating colorectal submucosal tumours (< 10 mm) originating in the muscularis propria.

METHOD

EE-L was used to treat 13 patients between January 2011 and January 2014. The tumour was sucked into a transparent cap and ligated at its base by a rubber band ligature attached to the tip of the endoscope. With the creation of a pseudo-stalk, the tumour was then enucleated using endoscopic dissection and the wound was closed with clips.

RESULTS

All tumours [median diameter 6.8 (4-10) mm] were successfully enucleated [procedure time 19 (11-27) min]. Histopathological examination identified 11 (84.6%) to be leiomyoma and 2 (15.4%) low-risk gastrointestinal stromal tumours. No perforations or massive haemorrhage occurred and there were no recurrences during a follow-up of 3-39 months.

CONCLUSION

EE-L is a successful technique for the removal of small colorectal tumours in the muscularis propria with few complications and enables a histopathological diagnosis. In this study, all the resected lesions had a benign pathology.

Validation of the MSKCC Gastrointestinal Stromal Tumor Nomogram and Comparison with Other Prognostication Systems: Single-Institution Experience with 289 Patients

PURPOSE

To validate the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram in a single-institution cohort of patients with gastrointestinal stromal tumors (GISTs), and to compare its predictive accuracy against other established risk classification systems, including the National Institutes of Health (NIH), Armed Forces Institute of Pathology (AFIP), and Joensuu criteria.

METHODS

We retrospectively reviewed 289 patients who underwent surgical resection for primary localized GISTs without adjuvant imatinib therapy and compared the actuarial recurrence-free survival (RFS) with the predicted RFS.

RESULTS

Tumors >5 cm in size, with high mitotic index, and which had ruptured were significantly associated with recurrent disease. The 2-year RFS was 77.2 % [95 % confidence interval (CI) 71.6-81.8], and the 5-year RFS was 67.9 % (95 % CI 61.7-73.4). The concordance probability of the nomogram of 2-year RFS was 0.71 (SE 0.02), and 5-year RFS was 0.71 (SE 0.19). The 2-year and 5-year MSKCC nomogram probability calculations and the AFIP criteria gave a better estimation of RFS compared to the NIH (p < 0.001) and Joensuu (p < 0.001) criteria. There was no significant difference between the predictive accuracy of the nomogram compared to the AFIP criteria.

CONCLUSIONS

The MSKCC nomogram slightly underestimated the probability of RFS after surgical resection of GISTs. It was associated with a significantly better predictive accuracy compared to the NIH and Joensuu. This study suggests that there is a wider than expected prognostic divergence between gastric GISTs versus GISTs arising from the small intestine.

Single-center experience of surgically resected gastrointestinal stromal tumors: A report of six cases, including a rare case involving the lower esophagus

Gastrointestinal stromal tumors (GISTs) are rare, but remain the most common GI mesenchymal neoplasms. In the present study, six cases of GIST are reported, and one of these cases, a patient with esophageal GIST, is reported in-depth. Certain recent developments in the clinical therapy of GISTs are also discussed. The records of all surgically-resected GI stromal tumors treated at the Al-Hada Military Hospital between January 2007 and December 2012 were reviewed. There were six cases of surgically resected GISTs during this time period, three males and three females, with a mean age of 69.3±16.4 years. The stomach was involved in 66.7% of cases, the small intestine in 16.7% and the esophagus, which is an extremely rare site, in 16.7% of cases. The most common symptom at presentation was abdominal pain, followed by GI bleeding. The mean tumor size was 8.7±6.3 cm. Surgery was indicated by the presence of the aforementioned symptoms or a tumor size >5 cm. All tumors were completely resected with histologically negative margins. The diagnoses were established by immunohistochemistry. Four patients were classified as possessing a high-grade variant, and were administered with tyrosine kinase inhibitors (TKIs). Following a mean follow up of 31 months, no recurrence or mortality was detected. Complete surgical resection with tumor-free margins is the standard treatment for GISTs, and TKIs should be used as adjuvant therapy if the risk of progressive disease is high.

Analysis of the amount of tissue sample necessary for mitotic count and Ki-67 index in gastrointestinal stromal tumor sampling

There are no established opinions concerning whether the amount of tissue affects the accuracy of histological analyses in gastrointestinal stromal tumors (GISTs). The aim of the present study was to investigate the appropriate amount of tissue sample needed for mitotic count based on the risk classification of GISTs and the Ki-67 index using the following three methods: endoscopic ultrasound-guided fine-needle aspiration (FNA), a novel sampling method called tunneling bloc biopsy (TBB), and biopsy forceps followed by TBB (Bf). Forty-three samples (12 FNA, 17 TBB and 14 Bf) diagnosed as GISTs by immunohistological analysis were utilized. The major and minor axes and overlay area of one piece of specimen (OPS) from the three sampling methods were measured using digital imaging software and were analyzed comparatively regarding the acquisition of histological data. The mean major and minor axes (mm) and overlay areas (mm2) were in the order of TBB > Bf > FNA. The evaluable rates by mitotic count and Ki-67 were, respectively, 75% (9/12) and 83.3% (10/12) for FNA samples, 100% (17/17) and 100% (17/17) for TBB samples, and 100% (14/14) and 100% (14/14) for Bf samples (P>0.05). Three FNA samples were judged unevaluable due to too small specimens in overall diagnosis including mitotic count and Ki-67, calculating the cut-off value for the overlay area of OPS as 0.17 mm2. Comparing the concordance rates between the pre- and post-operative samples, TBB samples was significantly better than FNA (P<0.05). Conclusively, while the amounts of tissues obtained by TBB and Bf are unnecessary for the histological assessment of mitotic count and Ki-67 index, developments of the FNA method are needed to minimize sample error. Considering the technical aspects, as well as the size of the specimens, could help to guide therapeutic planning and improve diagnostic yield for GI subepithelial tumors.

Laparo-endoscopic transgastric resection of gastric submucosal tumors

BACKGROUND

Laparoscopic and endoluminal surgical techniques have evolved and allowed improvements in the methods for treating benign and malignant gastrointestinal diseases. To date, only case reports have been reported on the application of a laparo-endoscopic approach for resecting gastric submucosal tumors (SMT). In this study, we aimed to evaluate the efficacy, safety, and oncologic outcomes of a laparo-endoscopic transgastric approach to resect tumors that would traditionally require either a laparoscopic or open surgical approach. Herein, we present the largest single institution series utilizing this technique for the resection of gastric SMT in North America.

METHODS

We performed a retrospective review of a prospectively collected patient database. Patients who presented for evaluation of gastric SMT were offered this surgical procedure and informed consents were obtained for participation in the study.

RESULTS

Fourteen patients were included in this study between August/2010 and January/2013. Eight (8) patients (57.1 %) were female and the median age was 56 years (range 29-78). Of the 14 cases, 8 patients (57.1 %) underwent laparo-endoscopic resection of SMTs with transgastric extraction, 5 patients (35.7 %) had conversions to traditional laparoscopic surgery, and 1 patient (7.2 %) was abandoned intraoperatively. The median operative time for this cohort was 80 min (range 35-167). Ten patients (71.4 %) had GISTs, 3 (21.4 %) had leiomyomas, and 1 (7.1 %) had schwannoma. There were no intraoperative complications. Two patients had postoperative staple line bleeding that required repeat endoscopy. The median hospital stay was 1 day (range 1-6) and there were no postoperative mortalities. At 12-month follow-up visit, only one GIST patient (10 %) had tumor recurrence.

CONCLUSION

Our experience suggests that this surgical approach is safe and efficient in the resection of gastric SMT with transgastric extraction. This study found no intraoperative complications and optimal oncologic outcomes during the follow-up period. Minimally invasive surgical approaches are emerging as a valid and potentially better approach for resecting malignancies; however, continued investigation is underway to further validate this data.

Single-incision laparoscopic surgery for a small-intestinal gastrointestinal stromal tumor: report of a case

Our report concerns a 64-year-old man with a small-intestinal gastrointestinal stromal tumor (GIST), which was successfully treated with single-incision laparoscopic surgery (SILS). Small-bowel endoscopy detected a submucosal tumor located approximately 10 cm from the ligament of Treitz in the wall of the proximal jejunum. Contrast-enhanced computed tomography revealed a tumor (diameter, 4 cm) containing high- and low-density areas in the proximal jejunum. On 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET), the tumor demonstrated intense FDG uptake (maximum standard uptake value, 3.82), whereas it displayed high signal intensity on diffusion-weighted magnetic resonance images. No metastatic lesions were observed. The patient was diagnosed with a jejunal GIST. Wedge resection of the jejunum was performed using the SILS procedure. The tumor was histopathologically diagnosed as a low-grade malignant GIST. SILS is a useful resection technique for small-intestinal GIST.

The diagnostic importance of matrix metalloproteinase-7 and nestin in gastrointestinal stromal tumors

BACKGROUND

The importance of the matrix metalloproteinase-7 (MMP-7) and nestin immunomarkers, C-kit proto-oncogene (CD117), and the efficiency of the Ki-67 proliferation index for gastrointestinal stromal tumors were evaluated.

MATERIAL AND METHODS

This study was conducted by examining the microscope slides of 72 patients with gastrointestinal stromal tumors that were sent to the pathology laboratory between 2007 and 2012. Immunohistochemical staining for CD117, MMP-7, nestin, and marker of proliferation Ki-67 was performed. The correlations between the positive results for Ki-67, CD117, MMP-7, and nestin were evaluated relative to the tumor characteristics of size, localization, grade, cellular type, cellularity, cytology type, growth pattern, ulceration, necrosis, hemorrhage, invasion depth, and lymph node metastasis.

RESULTS

The tumor was localized in the stomach in 42 of the patients, the intestines in 19, the colon in 7, and the rectum in 4. Comparisons among the groups showed that MMP-7 was correlated with the tumor grade (p<0.001), cellularity (p<0.009), cytologic atypia (p<0.001), ulceration (p=0.002), necrosis (p<0.001), and tumor size (p=0.001). Nestin was correlated with the tumor grade (p=0.013), and tumor size (p=0.024). Correlations among CD117, MMP-7, nestin, and Ki-67 were examined. Nestin and Ki-67 were both significantly correlated with CD117 and MMP-7 [(r=0.279, p=0.018), (r=0.322, p=0.006), (r=0.386, p=0.001), (r=0.386, p=0.002)], respectively.

CONCLUSIONS

MMP-7 and nestin may be beneficial as markers, given their sensitivity to gastrointestinal stromal tumors.

Multifocal small bowel stromal tumours presenting with peritonitis in an HIV positive patient

INTRODUCTION

The most common mesenchymal tumour of the gastrointestinal tract is stromal tumours (GISTs). Symptomatic GISTs can present with complications such as haemorrhage, obstruction and perforation. Complete surgical resection with negative margins is the mainstay of treatment but may be imprudent on emergent occasion. Tyrosine-kinase inhibitors (TKIs) have been revolutionary in the treatment of GISTs and have resulted in improved outcomes.

PRESENTATION OF CASE

A 41 year old HIV positive male presented with an acute history of abdominal pain and obstructive symptoms. Clinical examination revealed sepsis and peritonitis. One of the several small bowel tumours discovered at exploratory laparotomy was necrotic and perforated. The perforated tumour alone was resected and a small bowel internal hernia reduced. The patient made an uneventful recovery and will be considered for TKI therapy with a view to later re-operation.

DISCUSSION

GISTs very rarely perforate. The pathophysiology of stromal tumour necrosis is poorly understood. Multifocality and small bowel location are poor prognosticators and may occur in the setting of familial GISTs, specific syndromes and sporadic cases. There is no established association between HIV and GISTs.

CONCLUSION

Perforation occurs infrequently in ≤8% of symptomatic cases and poses increased risk of local recurrence. The surgical management of perforation takes precedence in an emergency. The surgeon must however take cognisance of the adherence to ideal oncologic principles where feasible. TKI therapy is invaluable if a re-exploration is to be later considered.

Ligation-assisted endoscopic enucleation for treatment of esophageal subepithelial lesions originating from the muscularis propria: a preliminary study

An innovative ligation-assisted endoscopic enucleation (EE-L) technique was developed for the diagnosis and treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria by combining endoscopic band ligation and endoscopic enucleation techniques. The aim of the study was to evaluate efficacy and safety of EE-L technique in the treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria. Forty-seven esophageal subepithelial lesions (smaller than 12 mm) originating from the muscularis propria in 44 patients were treated with EE-L between September 2010 and September 2012. The lesion was first aspirated into the transparent cap attached to the tip of endoscope. The elastic band was then released around its base. The purpose of ligation was to force the lesion to assume a polypoid form with a pseudostalk. Endoscopic enucleation was then performed until the tumor was completely enucleated from muscularis propria using a hook knife and forceps. All tumors (median diameter: 8.2 ± 2.3 mm, range: 4-12 mm) were enucleated completely. Histopathology identified 45 tumors (95.7%) as leiomyoma, 2 (4.3%) tumors as gastrointestinal stromal tumor with very low risk. The mean time of the EE-L procedure was 12.5 ± 4.6 minutes (range: 6-23 minutes). Two patients experienced self-limiting, non-life-threatening hemorrhage after EE-L. No perforation and massive hemorrhage requiring further endoscopic or surgical intervention occurred. There were no recurrences during the 6-24 months follow-up period. EE-L offers the option of localized treatment of small esophageal muscularis propria tumors (smaller than 12 mm) with relatively few complications and low mortality, and provides the advantage of allowing a histopathological diagnosis. All the resected lesions in this study had a benign pathology.

Surgical treatment of gastric gastrointestinal stromal tumor

Gastrointestinal stromal tumor is the most common mesenchymal tumor in the gastrointestinal tract and is most frequently developed in the stomach in the form of submucosal tumor. The incidence of gastric gastrointestinal stromal tumor is estimated to be as high as 25% of the population when all small and asymptomatic tumors are included. Because gastric gastrointestinal stromal tumor is not completely distinguished from other submucosal tumors, a surgical excisional biopsy is recommended for tumors >2 cm. The surgical principles of gastrointestinal stromal tumor are composed of an R0 resection with a normal mucosa margin, no systemic lymph node dissection, and avoidance of perforation, which results in peritoneal seeding even in cases with otherwise low risk profiles. Laparoscopic surgery has been indicated for gastrointestinal stromal tumors <5 cm, and the indication for laparoscopic surgery is expanded to larger tumors if the above mentioned surgical principles can be maintained. A simple exogastric resection and various transgastric resection techniques are used for gastrointestinal stromal tumors in favorable locations (the fundus, body, greater curvature side). For a lesion at the gastroesophageal junction in the posterior wall of the stomach, enucleation techniques have been tried preserve the organ's function. Those methods have a theoretical risk of seeding a ruptured tumor, but this risk has not been evaluated by well-designed clinical trials. While some clinical trials are still on-going, neoadjuvant imatinib is suggested when marginally unresectable or multiorgan resection is anticipated to reduce the extent of surgery and the chance of incomplete resection, rupture or bleeding.