Advances in immunotherapy of M2 macrophages and gastrointestinal stromal tumor.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal-derived tumors of the GI tract. They can occur throughout the GI tract, and the survival time of some patients can be improved by first-line targeted therapy with imatinib. However, there are some limitations with imatinib treatment. Immunotherapy for GIST has attracted much attention in recent years, and as one of the most abundant cells in the GIST microenvironment, M2 macrophages play an important role in disease progression. They have unique anti-inflammatory and pro-tumorigenic effects and are one target for immunotherapy. This review summarizes the connection between different factors and the programmed death receptor-1/programmed death ligand-1 pathway and M2 macrophages to reactivate or enhance anti-tumor immunity and improve imatinib efficacy, and to provide new ideas for GIST immunotherapy.

Extragastrointestinal Stromal Tumor in the Peritoneum: A Case Report.

Gastrointestinal stromal tumors (GIST) are tumors of mesenchymal origin, accounting for less than 1% of the primary neoplasms of the digestive tract, which can affect any segment of the gastrointestinal tract. However, they can also occur in other locations outside the gastrointestinal tract. In such situations, these are known as extragastrointestinal stromal tumors (eGIST). We present a 58-year-old male, who attended the emergency department due to asthenia, anorexia, heartburn, abdominal pain, and distension, who was ultimately diagnosed with an eGIST in the peritoneum. The immunohistochemistry pattern of the tumor sample obtained favored this diagnosis, especially demonstrated by the positivity for discovered on GIST protein 1 (DOG1) and negativity of smooth muscle markers. Due to the rarity of extragastrointestinal tumors and the even greater rarity of those originating in the peritoneum, the authors consider this a pertinent clinical case to be published due to its originality.

Large-scale, prospective observational study of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors in a real-world clinical setting.

Background: Regorafenib improves overall survival (OS) of patients with advanced progressive gastrointestinal stromal tumors (GISTs) after standard chemotherapy in phase III trials in the 3rd-line setting. This large-scale, prospective observational study evaluated the safety and effectiveness of regorafenib in Japanese patients with GIST in a real-world clinical setting. Methods: Patients with GIST received oral regorafenib at a maximum daily dose of 160 mg for weeks 1-3 of each 4-week cycle (dose could be modified at investigator's discretion). The primary objective was to assess safety, particularly significant adverse drug reactions (ADRs), as well as the frequency of occurrence of ADRs, hand and foot syndrome (HFS), discontinuation of treatment due to disease progression and adverse events. A Cox proportional hazards model was used to evaluate associations between OS or time to treatment failure (TTF) and baseline characteristics or HFS. Results: Between August 2013 and March 2021, 143 evaluable patients were enrolled. ADRs occurred in 90.2% of patients and led to treatment discontinuation in 28.3%. The most frequent ADRs were HFS, hypertension, and liver injury. The overall response rate was 11.3% and disease control rate 56.5% (RECIST) based on investigators' assessments. Median OS was 17.4 months (95% CI 14.24-23.68). Median TTF was 5.3 (95% CI 4.0-6.5) months. Improved OS and TTF responses occurred in patients with an Eastern Cooperative Oncology Group performance status (ECOG-PS) of 0 or 1. Conclusion: The outcomes in this real-world study were consistent with those seen in clinical trials. No new safety concerns were identified. Clinical trial registration: https://clinicaltrials.gov, identifier NCT01933958.

Transvaginal removal of rectal stromal tumor with Martius flap interposition: a feasible option for a large tumor at the anterior wall of the rectum.

Neoadjuvant imatinib treatment, followed by complete transvaginal removal, presents a feasible option for large rectal gastrointestinal tumors located on the anterior wall of the rectum and protruding into the vagina. The use of Martius flap interposition is convenient and can be employed to prevent rectovaginal fistula.

Primary gastrointestinal stromal tumor of the liver: a case report.

Introduction and importance: Primary gastrointestinal stromal tumors of the liver are exceedingly rare entities, presenting diagnostic and therapeutic challenges. The authors present a case of a 64-year-old male with a primary gastrointestinal stromal tumor (GIST) of the liver, emphasizing the importance of comprehensive diagnostic evaluation and multidisciplinary management in such uncommon cases. Case presentation: The patient presented with persistent hypochondriac pain, leading to the discovery of a hepatic mass. Diagnostic work-ups, including imaging studies and biopsy, confirmed the diagnosis of primary GIST in the liver. Following thorough multidisciplinary consultation, the patient underwent right anterior segmentectomy of the liver, performed by our experienced surgeon. Postoperative pathology confirmed the diagnosis of GIST, and the patient was advised to use adjuvant imatinib. Clinical discussion: Primary GISTs of the liver pose diagnostic challenges due to their rarity and varied clinical presentations. Imaging modalities, immunohistochemistry, and molecular genotyping are crucial in accurate diagnosis and treatment planning. Surgical resection remains the cornerstone of treatment for localized GISTs, with adjuvant therapy considered based on recurrence risk factors and molecular characteristics. Conclusion: This case highlights the need for multidisciplinary consultation in managing primary GISTs of the liver. Accurate diagnosis, surgical expertise, and personalized adjuvant therapy are crucial for better patient outcomes. Further research is necessary to enhance our understanding of prognostic factors and treatment strategies for these rare tumors.

Transcatheter arterial chemoembolization with tyrosine kinase inhibitor in the 12-year treatment of hepatic metastases from gastrointestinal stromal tumor: a case report.

Background: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the digestive tract, with surgery and tyrosine kinase inhibitor (TKI) therapy being its main treatment options. However, long-term use of TKIs may lead to drug resistance, which poses a challenge to the long-term survival of patients. We explore a new combination of transcatheter arterial chemoembolization (TACE) with TKI for liver metastasis (LM) of GIST to provide patients with more treatment options and better prognosis. Case Description: This case report describes the application of 6 TACE sessions in the 12-year treatment of multiple LM from small intestinal stromal tumors that were resistant to multiple TKIs. The patient, a 58-year-old male, underwent multiple surgical resections and drug therapies for the LM after a primary small bowel stromal tumor had been identified and resected following an onset symptom of abdominal pain in February 2012. Despite the challenges of drug resistance and economic considerations, 6 TACE sessions effectively controlled the tumor, winning valuable treatment time for the patient. Since the initiation of ripretinib 150 mg once daily in July 2023, the tumor has continued to shrink, with satisfactory drug tolerance. Conclusions: For GIST patients with LM, TACE combined with various TKI drugs could effectively control intrahepatic tumor progression and prolong patient survival. During six TACE sessions, the patient experienced liver tumor rupture and massive bleeding. However, the bleeding was completely stopped by embolization, and the lesion shrank. Our findings provide a new perspective and treatment strategy for the treatment of LM from GIST.

Survival of advanced/recurrent gastrointestinal stromal tumors treated with tyrosine kinase inhibitors in Taiwan: a nationwide registry study.

BACKGROUND: Most gastrointestinal stromal tumors (GISTs) harbor c-KIT or PDGFRA mutations. Administration of tyrosine kinase inhibitors (TKIs) has significantly improved the survival of patients with GISTs. We aimed to evaluate the clinical outcome of advanced or recurrent GIST patients in Taiwan. METHODS: Patients diagnosed between 2010 and 2020 were enrolled. The collected data included baseline characteristics, treatment pattern, treatment outcome, genetic aberrations and survival status. Progression-free survival (PFS) and overall survival (OS) were analyzed and plotted with the Kaplan-Meier method. Cox regression analysis was used to analyze the prognostic factors of survival. RESULTS: A total of 224 patients with advanced or recurrent GISTs treated with TKIs were enrolled. All patients received imatinib treatment. Ninety-three and 42 patients received sunitinib and regorafenib treatment, respectively. The 48-month PFS and OS rates for patients treated with imatinib were 50.5% and 79.5%, respectively. c-KIT exon 9 and PDGFRA mutations were prognostic factors for a poor PFS and PDGFRA mutation was a prognostic factor for a poor OS in patients treated with imatinib in multivariate Cox regression analysis. The median PFS of patients who received sunitinib treatment was 12.76 months (95% confidence interval (CI), 11.01-14.52). Patients with c-KIT exon 9 mutations had a longer PFS than those with other genetic aberrations. The median PFS of patients treated with regorafenib was 7.14 months (95% CI, 3.39-10.89). CONCLUSIONS: We present real-world clinical outcomes for advanced GIST patients treated with TKIs and identify mutational status as an independent prognostic factor for patient survival.

USP5 Promotes Ripretinib Resistance in Gastrointestinal Stromal Tumors by MDH2 Deubiquition.

Ripretinib, a broad-spectrum inhibitor of the KIT and PDGFRA receptor tyrosine kinases, is designated as a fourth-line treatment for gastrointestinal stromal tumor (GIST). It is tailored for patients resistant to imatinib, sunitinib, and regorafenib. As its increasing use, instances of resistance to ripretinib are becoming more frequent. Unfortunately, there are currently no scientifically mature treatment options available for patients resistant to ripretinib. Posttranslational modifications (PTMs) such as ubiquitination, in conjunction with its interplay with other modifications, play a collective role in regulating tumor initiation and progression. However, the specific association between ubiquitination and ripretinib resistance is not reported. Through proteome-ubiquitinome sequencing, increased levels of the USP5 protein and decreased ubiquitination in ripretinib-resistant GISTs are detected. Subsequent examination of the mass spectrometry findings validated the interaction through which TRIM21 governs USP5 expression via ubiquitination, and USP5 regulates MDH2 expression through deubiquitination, consequently fostering ripretinib resistance in GIST. Moreover, ZDHHC18 can palmitoylate MDH2, preventing its ubiquitination and further increasing its protein stability. The research underscores the correlation between posttranslational modifications, specifically ubiquitination, and drug resistance, emphasizing the potential of targeting the USP5-MDH2 axis to counteract ripretinib resistance in GIST.

A Gastrointestinal Stromal Tumor (GIST) and a Pseudocyst of the Pancreas: A Peculiar Case of Both Co-existing in the Same Patient.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal (GI) tract, typically originating from the interstitial cells of Cajal. The clinical presentations are variable according to their size and shape but rarely present as a palpable abdominal mass. Pancreatic pseudocysts are common complications of chronic pancreatitis characterized by fluid collections surrounded by a non-epithelialized wall of fibrous and granulation tissue. Patients may present with non-specific symptoms like abdominal pain, nausea, and vomiting and they generally have a history of acute pancreatitis. Small pseudocysts often resolve spontaneously, but larger ones often become symptomatic and may lead to complications. It is rare to find both a GIST of the stomach and a pseudocyst of the pancreas in the same patient. We present a unique case of a giant GIST and a pancreatic pseudocyst in a 72-year-old male who was experiencing abdominal pain and distension. Imaging revealed a massive lesion originating from the posterior gastric wall, which resembled a pseudocyst, along with a distinct cystic lesion adjacent to the pancreatic body. During surgical exploration, a complex interplay of both pathologies was discovered, requiring a comprehensive resection approach. The successful outcome highlights the importance of careful evaluation and personalized management in such rare cases.

Optimal management options for esophageal gastrointestinal stromal tumors (E-GIST).

OBJECTIVE: To explore the different treatment modalities for esophageal gastrointestinal stromal tumors (E-GIST) and their respective applicability and clinical outcomes. METHODS: This is a retrospective study in which consecutive patients diagnosed with E-GIST at our hospital from January 2017 to August 2023 were included. The clinical characteristics of all the patients as well as long-term quality of life were recorded and analyzed. RESULTS: A total of 23 (12 males, 11 females) E-GIST patients with a mean age of 56.7 ± 12.0 years were included in this study. Common symptoms, including upper abdominal pain, acid reflux, and heartburn, accounted for over 60 % of cases. Fifteen patients underwent endoscopic resection, five patients underwent surgical resection, two patients underwent surgical resection after receiving preoperative imatinib therapy, and one patient received conservative management. CONCLUSION: Different treatment strategies may be applied to the patients with E-GIST depending on the their clinical features. Our study provides insights into precise treatment for different patients. However, due to the rarity of the disease, it is challenging to collect a large sample size from a single center, necessitating more multicenter prospective large-scale studies.

Prospective evaluation of quantitative response parameter in patients with Gastrointestinal Stroma Tumor undergoing tyrosine kinase inhibitor therapy-Impact on clinical outcome.

The purpose of this study was to determine if dual-energy CT (DECT) vital iodine tumor burden (ViTB), a direct assessment of tumor vascularity, allows reliable response assessment in patients with GIST compared to established CT criteria such as RECIST1.1 and modified Choi (mChoi). From 03/2014 to 12/2019, 138 patients (64 years [32-94 years]) with biopsy proven GIST were entered in this prospective, multi-center trial. All patients were treated with tyrosine kinase inhibitors (TKI) and underwent pre-treatment and follow-up DECT examinations for a minimum of 24 months. Response assessment was performed according to RECIST1.1, mChoi, vascular tumor burden (VTB) and DECT ViTB. A change in therapy management could be because of imaging (RECIST1.1 or mChoi) and/or clinical progression. The DECT ViTB criteria had the highest discrimination ability for progression-free survival (PFS) of all criteria in both first line and second line and thereafter treatment, and was significantly superior to RECIST1.1 and mChoi (p < .034). Both, the mChoi and DECT ViTB criteria demonstrated a significantly early median time-to-progression (both delta 2.5 months; both p < .036). Multivariable analysis revealed 6 variables associated with shorter overall survival: secondary mutation (HR = 4.62), polymetastatic disease (HR = 3.02), metastatic second line and thereafter treatment (HR = 2.33), shorter PFS determined by the DECT ViTB criteria (HR = 1.72), multiple organ metastases (HR = 1.51) and lower age (HR = 1.04). DECT ViTB is a reliable response criteria and provides additional value for assessing TKI treatment in GIST patients. A significant superior response discrimination ability for median PFS was observed, including non-responders at first follow-up and patients developing resistance while on therapy.

Utilization of neoadjuvant therapy for localized gastric gastrointestinal stromal tumors and the association with survival.

BACKGROUND: For gastric gastrointestinal stromal tumors (GISTs), neoadjuvant imatinib is most often reserved for tumors near the gastroesophageal junction, multivisceral involvement, or limited metastatic disease. Whether localized gastric GISTs benefit from neoadjuvant therapy (NAT) remains unknown. We sought to examine factors associated with NAT utilization for localized gastric GISTs and evaluate implications on survival. METHODS: The National Cancer Database identified patients with localized gastric GISTs treated with NAT (2010-2020), excluding tumors extending beyond the gastric wall, located in the cardia, or with metastatic disease. Multivariable logistic regression assessed characteristics of NAT use. After 1:1 propensity score matching, Kaplan-Meier methods and multivariable Cox regression assessed overall survival (OS). RESULTS: Of 7203 patients, 762 (10.6%) received NAT followed by resection. On multivariable analysis, increasing tumor size was associated with NAT use (<2.0 cm vs 2.0-5.0 cm [odds ratio {OR}, 2.03; 95% CI, 1.19-3.47; P = .010] vs >5 cm [OR, 16.87; 95% CI, 10.02-28.40; P < .001]). After propensity score matching, 1506 patients remained. Median OS for NAT was 46.0 months vs 43.0 months for resection (P = .059), which was independently predictive of improved survival on multivariable analysis (hazard ratio [HR], 0.89; 95% CI, 0.80-0.99; P = .041). Subgroup analysis by tumor size showed no survival differences for tumors <2.0 cm or from 2.0 to 5.0 cm. Median OS was higher for tumors > 5.0 cm treated with NAT (NAT, 45.4 months [IQR, 29.5-65.9] vs upfront resection, 42.3 months [IQR 26.9-62.8]) and associated with improved survival on multivariable analysis (HR, 0.88; 95% CI, 0.78-0.99; P = .040). CONCLUSION: Although patients who received NAT had improved survival, this was primarily due to tumors >5.0 cm. Expanding NAT selection criteria to include localized gastric GISTs >5.0 cm may improve outcomes and warrants investigation through clinical trials.

Use of Endoscopic Ultrasound Elastography to Differentiate between Gastrointestinal Stromal Tumor and Leiomyoma Localized in the Upper Gastrointestinal Tract.

Background: Gastrointestinal stromal tumors (GISTs) have malignant potential. Distinction of GISTs from leiomyoma is important to the decision of follow-up or treatment for upper gastrointestinal tract subepithelial lesions (SELs). There are few studies on the evaluation of gastrointestinal SELs with endoscopic ultrasound (EUS) elastography. Aims: To evaluate the efficiency of strain ratio (SR) measurement and Giovannini's classification (Gc) by EUS elastography in differentiating GISTs from leiomyomas. Materials and methods: Twenty-three lesions with histopathological diagnoses of 13 GISTs and 10 leiomyomas were evaluated. The lesions' SR values were obtained from EUS reports retrospectively. Giovannini's classification was performed according to the elastography images recorded in the system. The effectiveness of SR and Gc in the distinction between GIST and leiomyomas was evaluated. Results: Twelve of the GISTs and 3 of the leiomyomas were with scores 4 and 5 according to Gc (p = 0.006). Gastrointestinal stromal tumors had a higher SR than leiomyomas (p = 0.001). For the diagnosis of GISTs, sensitivity/specificity/diagnostic accuracy were 92.3%/80%/87% for SR alone, 92.3%/70%/82.6% for Gc alone, and 84.6%/80%/82.6% for the use of both SR and Gc. Conclusions: This is the first study in which semi-quantitative (SR) and qualitative (Gc) methods were evaluated together for the distinction of GISTs and leiomyomas. The sensitivity of SR alone for diagnosing GIST is higher than that of Gc alone or the combination of both methods. Although SR alone does not diagnose GIST, it can be used as an auxiliary method in biopsy and follow-up decisions. How to cite this article: Erdem RE, Bektas M, Ellik ZM, et al. Use of Endoscopic Ultrasound Elastography to Differentiate between Gastrointestinal Stromal Tumor and Leiomyoma Localized in the Upper Gastrointestinal Tract. Euroasian J Hepato-Gastroenterol 2024;14(1):20-23.

Sub-regional CT Radiomics for the Prediction of Ki-67 Proliferation Index in Gastrointestinal Stromal Tumors: A Multi-center Study.

RATIONALE AND OBJECTIVES: The objective was to assess and examine radiomics models derived from contrast-enhanced CT for their predictive capacity using the sub-regional radiomics regarding the Ki-67 proliferation index (PI) in patients with pathologically confirmed gastrointestinal stromal tumors (GIST). METHODS: In this retrospective study, a total of 412 GIST patients across three institutions (223 from center 1, 106 from center 2, and 83 from center 3) was enrolled. Radiomic features were derived from various sub-regions of the tumor region of interest employing the K-means approach. The Least Absolute Shrinkage and Selection Operator (LASSO) regression was employed to identify features correlated with Ki-67 PI level in GIST patients. A support vector machine (SVM) model was then constructed to predict the high level of Ki-67 (Ki-67 index >8%), drawing on the radiomics features from each sub-region within the training cohort. RESULTS: After features selection process, 6, 9, 9, 7 features were obtained to construct SVM models based on sub-region 1, 2, 3 and the entire tumor, respectively. Among different models, the model developed by the sub-region 1 achieved an area under the receiver operating characteristic curve (AUC) of 0.880 (95% confidence interval [CI]: 0.830 to 0.919), 0.852 (95% CI: 0.770-0.914), 0.799 (95% CI: 0.697-0.879) in the training, external test set 1, and 2, respectively. CONCLUSION: The results of the present study suggested that SVM model based on the sub-regional radiomics features had the potential of predicting Ki-67 PI level in patients with GIST.

Common Benign Nerve Sheath Tumor at an Uncommon Location - Gastric Schwannoma.

Gastric schwannomas are rare types of gastrointestinal mesenchymal tumours that are slow-growing and mostly benign. They are usually asymptomatic. In some cases, nonspecific gastric symptoms, palpable mass, and bleeding can be seen. A definitive diagnosis requires pathological and immunohistochemical examination, and surgical resection offers an excellent prognosis with uncommon recurrence. We present a case of a 62-year-old woman who underwent exploratory laparotomy and wedge resection with preoperative diagnosis as gastrointestinal stromal tumor and postoperatively diagnosed as schwannoma on histopathology.

Clinicopathological Characteristics and the First Mutational Analysis of Gastrointestinal Stromal Tumors From Mexico: A Single Institution Experience.

Background Gastrointestinal stromal tumors (GISTs) arise from Cajal's interstitial cell precursors and display a variety of genetic mutations, primarily in the KIT and PDGFRA genes. These mutations are linked to tumor location, prognosis, and response to treatment. This study delves into the mutational patterns of GISTs in a Mexican population and their impact on overall survival (OS) and disease-free survival (DFS). Methodology This retrospective study examined 42 GIST cases diagnosed at the Oncology Hospital of the National Medical Center XXI Century between January 2018 and December 2020. Clinical, histological, and immunohistochemical data were gathered, and mutational analysis of KIT and PDGFRA genes was conducted using second-generation sequencing. Results The study group consisted of 52.4% females and 47.6% males, with an average age of 62.6 years. The most common tumor site was the stomach (59.5%), followed by the small intestine (26.2%). KIT mutations were detected in 71.4% of cases, predominantly involving exon 11. PDGFRA mutations were observed in 7.1% of cases. Recurrence was noted in 9.5% of patients, all with high-risk tumors. No significant link was identified between specific mutations and OS or DFS. Conclusions This investigation sheds light on the genetic landscape of GISTs in the Mexican population. While no significant association was established between particular mutations and survival outcomes, the study emphasizes the importance of molecular profiling in treatment decision-making. Further studies with larger sample sizes and longer follow-up periods are necessary to validate these results and explore their clinical relevance.

The immunotherapy in gastrointestinal stromal tumors.

Using Tyrosine Kinase Inhibitors (TKIs) for gastrointestinal stromal tumors (GIST) has significantly reduced the risk of recurrence and prolonged survival. Immunotherapy has demonstrated efficacy in multiple solid tumors, but its effectiveness in GIST remains uncertain. Although early clinical studies indicate good tolerability of immunotherapy in patients, the efficacy is not as desired. Therefore, identifying the subset of GIST patients who benefit from immunotherapy and coordinating the relationship between immunotherapy and TKI treatment are crucial issues to be explored. In this review, we aims to provide a retrospective analysis of relevant literature and find that GIST patients exhibit a rich presence of tumor-infiltrating immune cells, which play critical roles in the immune surveillance and evasion processes of tumors. This review incorporates a selection of 48 articles published between 2002 and 2023, sourced from PubMed, EBSCO, and Google Scholar databases.

Pilot Study by Liquid Biopsy in Gastrointestinal Stromal Tumors: Analysis of PDGFRA D842V Mutation and Hypermethylation of SEPT9 Presence by Digital Droplet PCR.

Tissue biopsy remains the standard for diagnosing gastrointestinal stromal tumors (GISTs), although liquid biopsy is emerging as a promising alternative in oncology. In this pilot study, we advocate for droplet digital PCR (ddPCR) to diagnose GIST in tissue samples and explore its potential for early diagnosis via liquid biopsy, focusing on the PDGFRA D842V mutation and SEPT9 hypermethylated gene. We utilized ddPCR to analyze the predominant PDGFRA mutation (D842V) in surgical tissue samples from 15 GIST patients, correlating with pathologists' diagnoses. We expanded our analysis to plasma samples to compare DNA alterations between tumor tissue and plasma, also investigating SEPT9 gene hypermethylation. We successfully detected the PDGFRA D842V mutation in GIST tissues by ddPCR. Despite various protocols to enhance mutation detection in early-stage disease, it remained challenging, likely due to the low concentration of DNA in plasma samples. Additionally, the results of Area Under the Curve (AUC) for the hypermethylated SEPT9 gene, analyzing concentration, ratio, and abundance were 0.74 (95% Confidence Interval (CI): 0.52 to 0.97), 0.77 (95% CI: 0.56 to 0.98), and 0.79 (95% CI: 0.59 to 0.99), respectively. As a rare disease, the early detection of GIST through such biomarkers is particularly crucial, offering significant potential to improve patient outcomes.

A Rare Case of Colonic Gastrointestinal Stromal Tumor.

Gastrointestinal stromal tumors (GISTs) are a type of mesenchymal tumor of the gastrointestinal tract that originate anywhere in the gastrointestinal tract, with the colon and appendix being the least recorded sites of occurrence. The following case report is that of a colonic GIST in a 53-year-old male and its histologic type. Included are notes on the recent additions and updates in the risk stratification of GISTs occurring in unusual sites with the relevant immunohistochemistry.

Transvaginal resection of a gastrointestinal stromal tumor of the rectum: a case report.

BACKGROUND: The most common curative treatment for gastrointestinal stromal tumors (GISTs) is local excision. For rectal GISTs, however, local excision is difficult because of the anatomical features of the rectum. The optimal surgical approach is still under debate, and less invasive methods are desired. We herein report a case of transvaginal resection of a rectal GIST in a young woman. CASE PRESENTATION: A 21-year-old woman was diagnosed with a resectable GIST in the anterior rectal wall and underwent transvaginal tumor resection. The posterior vaginal wall was incised, revealing the tumor fully covered by the rectal mucosa. The rectal adventitia and muscular layer were incised, and the tumor was resected en bloc without rupture. The postoperative course was favorable, and the patient was discharged on postoperative day 12. No findings consistent with recurrence were present 6 months postoperatively. CONCLUSION: Transvaginal tumor resection is a treatment option as a minimally invasive procedure for GISTs in the anterior rectal wall in female patients.