Laparoscopic resection of pedunculated extraluminal gastrointestinal stromal tumor (GIST) from gastric greater curvature: a case report and review of literature

Abstract

Introduction and importance:

Gastric gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and exophytic lesions from the greater curvature may initially mimic hepatic or pancreatic masses. Extraluminal pedunculated gastric GISTs are exceptionally rare, and laparoscopic resection of large pedunculated tumors of the greater curvature with oncologic margins is exceptionally rare and rarely described in the literature.

Case presentation:

A 64‑year‑old Middle Eastern woman presented with a 2‑month history of dull, non‑radiating epigastric pain without bleeding, weight loss, or obstructive symptoms. Endoscopic ultrasonography (EUS) and contrast‑enhanced computed tomography revealed a 14 × 8 cm, well‑circumscribed, completely extraluminal mass arising from the gastric greater curvature and attached by a pedunculated stalk, with no evidence of metastasis. She underwent laparoscopic wedge resection with an approximately 1 cm gross margin around the stalk and two‑layer closure, had an uncomplicated postoperative course, and histopathology confirmed a gastric GIST.

Clinical discussion:

This case adds to the limited literature on pedunculated extraluminal gastric GISTs and demonstrates that, in anatomically favorable locations on the greater curvature, laparoscopic wedge resection can achieve R0 margins while minimizing morbidity. EUS-guided biopsy was deferred to avoid seeding, given unambiguous imaging of gastric origin, and neoadjuvant imatinib was not initiated as the tumor was upfront resectable with anticipated clear margins. As a tumor exceeding 10 cm, it is classified as high-risk by the Joensuu criteria, and adjuvant imatinib was offered accordingly.

Conclusion:

A large pedunculated extraluminal GIST of the gastric greater curvature can be safely managed by stomach-preserving laparoscopic wedge resection with R0 excision, supporting minimally invasive surgery as a viable option for carefully selected exophytic or pedunculated gastric GISTs and highlighting the importance of meticulous preoperative imaging and strict adherence to oncologic principles.

Introduction

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, with an annual incidence of 10–15 cases per million population^[1^]. Approximately 60% originate in the stomach, with approximately 24% arising from the greater curvature and exhibiting predominantly exophytic growth^[2,3^]. Extraluminal pedunculated gastric GISTs constitute an exceedingly rare subtype; only five cases are documented in PubMed-indexed literature, and laparoscopic resection of greater curvature pedunculated GISTs with R0 oncologic margins is exceptionally rarely described in the literature^[4,5^]. We present a case contributing to this very limited experience: a large pedunculated extraluminal GIST resected from the gastric greater curvature with R0 margins of 1 cm, demonstrating the technical feasibility of minimally invasive surgery for this rare morphology. This case report has been prepared in line with the SCARE 2025 checklist^[6^].

Case presentation

A 64-year-old Middle Eastern woman (body mass index of 25 kg/m²) with well-controlled hypertension presented with a 2-month history of dull epigastric pain without nausea, vomiting, bleeding, or weight loss. She had no family history of gastrointestinal malignancy. Her past surgical history included total abdominal hysterectomy with bilateral salpingo-oophorectomy. Abdominopelvic ultrasonography identified a large solid mass adjacent to the left hepatic lobe and gastric fundus, initially suggesting a hepatic origin. Endoscopic ultrasonography (EUS) demonstrated a well-defined extraluminal solid mass compressing the gastric fundus, arising from the muscularis propria of the greater curvature. EUS-guided fine-needle biopsy was not performed; the characteristic appearance of a hypoechoic mass arising from the muscularis propria without high-risk features (no irregular borders, cystic spaces, or lymphadenopathy), combined with unambiguous imaging evidence of gastric origin, led the multidisciplinary team to judge that the risk of tumor seeding outweighed the diagnostic benefit, and a direct surgical approach was favored. Incidental findings included pangastritis, a non-bleeding antral ulcer, and a mild hiatal hernia. Contrast-enhanced computed tomography (CT) confirmed a 14 × 8 cm solid mass abutting the gastric fundus and greater curvature with no metastases (Fig. 1). Laboratory investigations, including full blood count, renal function, lipid profile, and liver enzymes, were within normal limits. Physical examination revealed mild epigastric tenderness without guarding or a palpable mass. Differential diagnoses included hepatic or pancreatic neoplasm and submucosal gastric tumor; however, origin from the muscularis propria on imaging made GIST the most probable diagnosis. Neoadjuvant imatinib was considered but not initiated, because the tumor was deemed technically resectable with anticipated clear margins on preoperative imaging and occupied an anatomically favorable position on the greater curvature, amenable to laparoscopic wedge resection without the need for gastric reconstruction. A timeline of clinical events is presented in Table 1. Written informed consent was obtained for both surgery and publication. Antihypertensive medications were optimized preoperatively, and the patient was kept nil by mouth for 8 hours before surgery. Diagnostic laparoscopy confirmed a large, well-circumscribed, completely extraluminal mass arising from the greater curvature via a distinct pedunculated stalk (approximately 3 cm in diameter) (Fig. 2), with no peritoneal, hepatic, or nodal metastases. Wedge resection was preferred over distal gastrectomy because the pedunculated attachment to the greater curvature allowed stomach-preserving margin excision without compromising luminal integrity. Laparoscopic wedge resection was performed with an approximately 1 cm gross margin around the stalk, selected intraoperatively in accordance with oncologic principles (Fig. 3). Following careful dissection and vascular control, the stalk was transected, and the mass excised en bloc. The gastric defect was closed in two layers using 2-0 Vicryl and 2-0 Prolene (a hand-sewn closure was chosen over a stapled closure to allow precise tailoring of the defect and ensure an airtight repair); airtight closure and hemostasis were confirmed. The specimen was retrieved in an endoscopic bag, and a drain was placed. The procedure was performed by fellowship-trained advanced laparoscopic surgeons at a high-volume tertiary referral center without intraoperative complications or deviation from the planned approach. The patient was managed in the intensive care unit overnight and transferred to the surgical ward on postoperative day 2. A clear liquid diet was introduced and advanced to a regular diet by 72 hours. She was discharged in good condition without early complications. Histopathology revealed a spindle-cell GIST measuring 14 × 8 cm with a mitotic index of 5 per 5 mm²; R0 resection was confirmed. By the modified National Institutes of Health (NIH)/Joensuu criteria, this represents a high-risk gastric GIST: a gastric tumor exceeding 10 cm in maximum dimension independently satisfies the high-risk threshold under the Joensuu modified NIH criteria, irrespective of mitotic count. Adjuvant imatinib (400 mg daily for 3 years) was discussed with and offered to the patient in a multidisciplinary setting, in accordance with current guidelines for high-risk GISTs. Surveillance was planned with contrast-enhanced CT every 6–12 months. At 6-month follow-up, imaging showed no evidence of recurrence.

Figure 1.

CT scan showing an extraluminal mass at the gastric fundus.

Table 1.

Timeline of clinical events.

Time point	Event
2 months before presentation	Onset of dull, non-radiating epigastric pain
Initial consultation	Abdominopelvic ultrasonography showing mass near left hepatic lobe/fundus
Pre-operative evaluation	EUS confirming extraluminal mass from greater curvature; CT showing 14 × 8 cm mass without metastasis
Day 0 (surgery)	Laparoscopic wedge resection with 1 cm margin and two-layer closure
Postoperative day 1	ICU monitoring, hemodynamically stable
Postoperative day 2	Transfer to surgical ward, diet advancement
Postoperative day 3	Discharge in good general condition
Follow-up	Asymptomatic, no evidence of recurrence

Figure 2.

Laparoscopic view of a pedunculated GIST from the greater curvature.

Figure 3.

Laparoscopic wedge resection with a 1 cm margin.

HIGHLIGHTS

• Large pedunculated extraluminal gastric gastrointestinal stromal tumors (GISTs) of the greater curvature are exceptionally rare and may mimic hepatic or pancreatic masses on initial imaging.

• High-quality endoscopic ultrasonography and contrast-enhanced computed tomography were essential to confirm the gastric origin and enable stomach-preserving laparoscopic wedge resection.

• Laparoscopic wedge resection with a 1 cm gross margin achieved R0 excision in a 14 × 8 cm pedunculated GIST, without intraoperative rupture or the need for reconstruction.

• The patient had an uncomplicated postoperative course, with rapid recovery and high satisfaction with the minimally invasive approach.

• This case supports laparoscopic management as a viable option for carefully selected pedunculated extraluminal gastric GISTs of the greater curvature.

Patient perspective

The patient reported prompt relief of epigastric pain and expressed satisfaction with the minimally invasive approach, cosmetic outcome, and rapid recovery.

Discussion

Exophytic tumors arising from the fundus or greater curvature may project into the abdominal cavity and mimic hepatic or pancreatic masses − as occurred in our patient, whose lesion was initially interpreted as hepatic on ultrasonography^[7^]. EUS and contrast-enhanced CT were essential to confirm origin from the muscularis propria and plan a stomach-preserving resection. Pedunculated extraluminal gastric GISTs form a particularly rare subset. Ogawa et al reported an extraluminally pedunculated gastric GIST with pancreatic metastasis after R0 resection, illustrating that pedunculated morphology does not imply indolent biology^[3^]. Our patient had isolated epigastric pain without bleeding or obstruction despite a 14 × 8 cm tumor, reinforcing that clinical presentation is driven more by the direction of growth than tumor size alone^[8^]. Historically, open surgery was recommended for large gastric GISTs owing to concerns about rupture, margin adequacy, and technical difficulty. However, multiple series now support laparoscopic wedge resection for appropriately located GISTs − including tumors ≥5 cm − with comparable R0 rates, low morbidity, and equivalent long-term oncologic outcomes to open surgery, alongside reduced pain and shorter hospitalization^[9^]. Lesions on the greater curvature and anterior wall are considered particularly suitable for minimally invasive resection because they allow straightforward wedge excision and primary closure without significant luminal compromise^[10^]. In our case, the discrete pedicle on the greater curvature enabled precise circumferential resection with a 1 cm margin, two-layer closure, and uneventful recovery, provided atraumatic handling, early vascular control, and use of a retrieval bag were maintained. Such tailored, stomach-preserving minimally invasive strategies reflect the broader principle of individualized operative planning for rare gastrointestinal pathologies in anatomically challenging presentations^[11^]. Pathologic assessment − including tumor size, mitotic index, and immunohistochemistry − remains central to risk stratification and decisions regarding adjuvant imatinib^[6^]. Although gastric location generally confers a better prognosis than small bowel or rectal GIST, reports of aggressive behavior in some pedunculated and exophytic tumors support individualized risk assessment and structured postoperative surveillance. A literature review (Table 2) summarizes previously reported extraluminal pedunculated gastric GISTs, which were predominantly managed by open or combined open-laparoscopic resection, emphasizing the technical challenges of vascular control and oncologic margin achievement in this rare morphology^[1–5^].

Table 2.

Reported extraluminal pedunculated gastric GISTs.

Author	Year	Age, sex	Location (gastric)	Size (cm)	Growth pattern & stalk	Clinical presentation	Surgical approach
Lisboa et al[1]	2024	61/Female	Stomach (greater curvature)	~25	Giant pedunculated gastric GIST, Extragastric growth	Largely asymptomatic	Resection (modality not specified)
Sacerdoțianu et al[2]	2023	47/Male	Exophytic gastric (including greater curvature)	Mostly >10	Exophytic (extraluminal), pedunculated-like	Abdominal mass, pressure symptoms	Mixed open/laparoscopic
Ogawa et al[3]	2021	70/Female	Dorsal wall/upper body (≈greater curvature)	Pre-op CT: 16 × 10 × 20; gross: 30 × 20 × 6	Completely extraluminal, pedunculated from muscularis propria; long stalk	Abdominal pulsation, palpable mass, left abdominal mass	Open resection including pedicle and small gastric cuff
Min Wang et al[4]	2020	62/Female	Gastric, Extragastic with pedicle	Not specified (large)	Extra-gastric, pedunculated gastric GIST	Incidental finding on ultrasound; solid-cystic lower-liver mass	Surgical resection
Kimura et al[5]	2004	84/Female	Lesser curvature, Extragastric	20	Pedunculated, Extragastric growth	Investigation for anemia; barium defect; abdominal CT showed mass displacing spleen	Surgical resection

Strengths and limitations

This report provides detailed imaging, intraoperative, and pathological correlation for a rare entity. Limitations include the single-case design and relatively short follow-up, which restrict generalizability. Key lessons include the value of meticulous preoperative imaging to define tumor origin, careful intraoperative handling to prevent rupture, and the selection of anatomically favorable lesions for laparoscopic resection.

Conclusion

This case demonstrates that a large pedunculated extraluminal GIST on the gastric greater curvature can be safely managed with laparoscopic wedge resection, achieving R0 excision with negative margins while respecting oncologic principles. When supported by high-quality preoperative imaging, appropriate case selection, and meticulous technique, laparoscopy offers adequate oncologic control with reduced postoperative pain, shorter hospital stay, and faster recovery, making it an attractive first-line option for anatomically favorable pedunculated or exophytic gastric GISTs.

Use of artificial intelligence

Generative AI (Perplexity, powered by GPT-5.1; accessed 12 April 2026) was used only for language refinement during revision on de-identified text with no patient identifiers or images. It was not used for data generation, clinical decision-making, statistical analysis, or image interpretation. All outputs were fact-checked against the original case, imaging, and pathology records. The authors take full responsibility for the final content, and AI was not credited as an author.

Ethical approval

Ethical approval is not required for anonymized single-patient case reports at our institution.

Consent

Written informed consent was obtained from the patient for the publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Source of funding

No funding was received for this case report.

Author contributions

H.R.S. performed the surgery, collected clinical and imaging data, conducted the primary literature review, and drafted the initial version of the manuscript. M.T. (senior surgeon and supervisor) conceived the idea of reporting this case with a literature review, provided critical surgical input, and substantially revised the manuscript for important intellectual content. S.A.S.S. assisted in surgery, contributed to the literature search and comparison with previously reported cases, and approved the final manuscript. A.H.L. assisted in the surgery, contributed to data collection and organization of intraoperative details, and revised the manuscript draft. K.N. contributed to perioperative management, interpretation of imaging and pathological findings, and critically reviewed and edited the manuscript. H.Z.M.A. participated in clinical decision-making, contributed to data interpretation and figure selection, and reviewed the manuscript for accuracy and clarity. F.E.N. contributed to the preparation, creation of the published work, specifically visualization. All authors read and approved the final version of the manuscript and agreed to be accountable for all aspects of the work.

Conflicts of interest disclosure

The authors declare that they have no competing interests.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Hamid Reza Soltani.

Provenance and peer review

Not applicable.

Data availability statement

All data generated or analyzed during this case report are included in this published article and its accompanying images.